soc: adi: Extract max32 flashprog section to a dedicated linker script

Extracts the max32 flashprog linker section to a dedicated linker script
that is conditionally included only when the flash driver is enabled.
This prepares max32 soc family to set SOC_LINKER_SCRIPT directly to the
common arm cortex-m linker script.

Signed-off-by: Maureen Helm <maureen.helm@analog.com>

soc/adi/max32/CMakeLists.txt

@@ -5,4 +5,6 @@ zephyr_include_directories(${ZEPHYR_BASE}/drivers)
 zephyr_include_directories(common)
 zephyr_sources(soc.c)
 
+zephyr_linker_sources_ifdef(CONFIG_SOC_FLASH_MAX32 SECTIONS flash.ld)
+
 set(SOC_LINKER_SCRIPT ${ZEPHYR_BASE}/include/zephyr/arch/arm/cortex_m/scripts/linker.ld CACHE INTERNAL "")

soc/adi/max32/flash.ld

@@ -0,0 +1,10 @@
+/*
+ * Copyright (c) 2023 Analog Devices, Inc.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+SECTION_DATA_PROLOGUE(.flashprog,, SUBALIGN(4))
+{
+	KEEP(*(.flashprog*)) /* Flash program */
+}