Stm32h7dks: Fix sdram available size for stm32h750b-dk and stm32h745i_disco

[rvosk]

According to UM2488 section 6.12[1], the available SDRAM size is only 8MB
by hardware design, though 128Bit SDRAM is connected.

Link: https://www.st.com/resource/en/user_manual/um2488-discovery-kits-with-stm32h745xi-and-stm32h750xb-mcus-stmicroelectronics.pdf [1]

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[rvosk]

It's a bit wired, still failed here, I dunno what's wrong

INFO: Potential tag based filters: {'bluetooth', 'cmsis_dsp', 'posix', 'net', 'mcumgr', 'test_framework', 'wifi', 'kernel'}
INFO: found boards: stm32h750b_dk,stm32h750b_dk/stm32h750xx/ext_flash_app,stm32h745i_disco/stm32h745xx/m7,stm32h745i_disco/stm32h745xx/m4
Traceback (most recent call last):
  File "/home/runner/work/zephyr/zephyr/zephyr/./scripts/ci/test_plan.py", line 549, in <module>
Changed files:
=========
boards/st/stm32h745i_disco/stm32h745i_disco_stm32h745xx_m7.dts
boards/st/stm32h750b_dk/stm32h750b_dk-common.dtsi
=========
    f.process()
  File "/home/runner/work/zephyr/zephyr/zephyr/./scripts/ci/test_plan.py", line 1[45](https://github.com/zephyrproject-rtos/zephyr/actions/runs/19567489845/job/56032927602?pr=99799#step:7:46), in process
    self.find_boards()
  File "/home/runner/work/zephyr/zephyr/zephyr/./scripts/ci/test_plan.py", line 292, in find_boards
    self.resolved_files.extend(list(filter(resolved_filter)))
                                    ^^^^^^^^^^^^^^^^^^^^^^^
TypeError: filter expected 2 arguments, got 1
Error: Process completed with exit code 1.

[rvosk]

It's a bit wired, still failed here, I dunno what's wrong

INFO: Potential tag based filters: {'bluetooth', 'cmsis_dsp', 'posix', 'net', 'mcumgr', 'test_framework', 'wifi', 'kernel'}
INFO: found boards: stm32h750b_dk,stm32h750b_dk/stm32h750xx/ext_flash_app,stm32h745i_disco/stm32h745xx/m7,stm32h745i_disco/stm32h745xx/m4
Traceback (most recent call last):
  File "/home/runner/work/zephyr/zephyr/zephyr/./scripts/ci/test_plan.py", line 549, in <module>
Changed files:
=========
boards/st/stm32h745i_disco/stm32h745i_disco_stm32h745xx_m7.dts
boards/st/stm32h750b_dk/stm32h750b_dk-common.dtsi
=========
    f.process()
  File "/home/runner/work/zephyr/zephyr/zephyr/./scripts/ci/test_plan.py", line 1[45](https://github.com/zephyrproject-rtos/zephyr/actions/runs/19567489845/job/56032927602?pr=99799#step:7:46), in process
    self.find_boards()
  File "/home/runner/work/zephyr/zephyr/zephyr/./scripts/ci/test_plan.py", line 292, in find_boards
    self.resolved_files.extend(list(filter(resolved_filter)))
                                    ^^^^^^^^^^^^^^^^^^^^^^^
TypeError: filter expected 2 arguments, got 1
Error: Process completed with exit code 1.

I see, this is caused by the CI script itself. All recent PRs all fail here, for example: #99791

[etienne-lms]

I've tested the changes and confirmed that the 2 boards can access only the first 8MByte of their SDRAM.
Accessing from the CPU above that limit ends in an imprecise data bus errors.

I wanted to use tests/drivers/memc/ to check accesses but I saw some issues both in the test and possibly in the FMC SDRAM timings also. I'll create a P-R to share.
(edited) => see #99824

[etienne-lms]

The CI test issue has been fixed: #99812.
Could you rebase your change?