samples: drivers: adc: enhance test scenarios filtering and config

Make samples' test scenarios depend on the existence of required DT
elements.
Now that test scenarios are filtered automatically depending on DT,
remove platform_allow/exclude from generic test scenarios.
Add more integration platforms to cover most ADC IPs/drivers.
Remove redundant platforms that are testing the same IP/Driver,
or only keep 1 platform from each SoC series.

Signed-off-by: Abderrahmane JARMOUNI <[email protected]>

Author: JarmouniA

boards/gd/gd32f350r_eval/gd32f350r_eval.yaml

@@ -13,4 +13,5 @@ toolchain:
 supported:
   - watchdog
   - dma
+  - adc
 vendor: gd

boards/nxp/lpcxpresso55s36/lpcxpresso55s36.yaml

@@ -14,6 +14,7 @@ toolchain:
   - zephyr
   - gnuarmemb
 supported:
+  - adc
   - arduino_gpio
   - can
   - dac