platform: stm32wba65i_dk: Fix install for STM32_FLASH_LAYOUT_BEGIN_OFFSET

Install a flash_layout.h header file that consider the value of build
directive STM32_FLASH_LAYOUT_BEGIN_OFFSET passed when building TF-M.

Without this change, generic code building non-secure application,
like when Zephyr builds TF-M regression test non-secure application,
do not consider this directive and use flash_layout.h as if
STM32_FLASH_LAYOUT_BEGIN_OFFSET was 0.

Signed-off-by: Ahmad EL JOUAID <[email protected]>
Change-Id: Icc20b09041f7bcb0287c932e6a2a13f6fa73e268

(cherry picked from commit eed47eff0e5ab8cac2126e24cb4e84e1148a9f68)

Author: ahmadstm

platform/ext/target/stm/stm32wba65i_dk/CMakeLists.txt

@@ -63,11 +63,22 @@ install(DIRECTORY   ${STM_COMMON_DIR}/hal/accelerator/
         FILES_MATCHING PATTERN "*.h")
 
 install(FILES
-    ${STM32WBA65I_DK_DIR}/partition/flash_layout.h
     ${STM32WBA65I_DK_DIR}/partition/region_defs.h
     DESTINATION ${INSTALL_PLATFORM_NS_DIR}/partition
 )
 
+# Install a flash_layout.h header file that consider STM32_FLASH_LAYOUT_BEGIN_OFFSET
+# TF-M was built with.
+install(FILES
+    ${STM32WBA65I_DK_DIR}/partition/flash_layout.h
+    DESTINATION ${INSTALL_PLATFORM_NS_DIR}/partition/gen_layout
+)
+
+file(WRITE ${INSTALL_PLATFORM_NS_DIR}/partition/flash_layout.h
+  "#define STM32_FLASH_LAYOUT_BEGIN_OFFSET ${STM32_FLASH_LAYOUT_BEGIN_OFFSET}\n"
+  "#include \"gen_layout/flash_layout.h\"\n"
+)
+
 install(DIRECTORY   ${PLATFORM_DIR}/ext/common
                     ${PLATFORM_DIR}/ext/driver
         DESTINATION ${INSTALL_PLATFORM_NS_DIR}/ext)