samples: flash_shell: Enable on all platforms with a flash driver

Try and build the flash_shell on all platforms that have a flash driver
rather than a limited set of know platforms.  This hopefully acts as a
build coverage test for all the flash drivers.

The flash shell requires around 10K of memory so limit it to systems
with 12K or more.

Signed-off-by: Kumar Gala <[email protected]>

Author: galak

samples/drivers/flash_shell/Kconfig

@@ -0,0 +1,9 @@
+# Copyright (c) 2020, Linaro Ltd.
+# SPDX-License-Identifier: Apache-2.0
+
+source "Kconfig.zephyr"
+
+if ARM_MPU
+config MPU_ALLOW_FLASH_WRITE
+	def_bool y
+endif

samples/drivers/flash_shell/prj.conf

@@ -7,4 +7,3 @@ CONFIG_FLASH=y
 # If that's the case and you're interested in the flash layout, enable
 # it here.
 # CONFIG_FLASH_PAGE_LAYOUT=y
-CONFIG_MPU_ALLOW_FLASH_WRITE=y

samples/drivers/flash_shell/sample.yaml

@@ -4,6 +4,7 @@ sample:
   name: Flash shell
 tests:
   sample.drivers.flash.shell:
-    platform_whitelist: 96b_carbon frdm_k64f frdm_kw41z frdm_kl25z nucleo_f746zg
     tags: flash shell
+    filter: CONFIG_FLASH_HAS_DRIVER_ENABLED
     harness: keyboard
+    min_ram: 12