boot: zephyr: config: Introduce MCUBOOT_BOOT_MAX_ALIGN Kconfig symbol

Allow setting CONFIG_MCUBOOT_BOOT_MAX_ALIGN to apply a programmable block
in flash. Move the chosen flash write block size logic to Kconfig.

Signed-off-by: Pieter De Gendt <[email protected]>

Author: pdgendt

boot/zephyr/include/mcuboot_config/mcuboot_config.h

@@ -430,11 +430,8 @@
 #endif
 
 /* Support 32-byte aligned flash sizes */
-#if DT_HAS_CHOSEN(zephyr_flash)
-    #if DT_PROP_OR(DT_CHOSEN(zephyr_flash), write_block_size, 0) > 8
-        #define MCUBOOT_BOOT_MAX_ALIGN \
-            DT_PROP(DT_CHOSEN(zephyr_flash), write_block_size)
-    #endif
+#if defined(CONFIG_MCUBOOT_BOOT_MAX_ALIGN) && CONFIG_MCUBOOT_BOOT_MAX_ALIGN > 8
+#define MCUBOOT_BOOT_MAX_ALIGN CONFIG_MCUBOOT_BOOT_MAX_ALIGN
 #endif
 
 #ifdef CONFIG_MCUBOOT_BOOTUTIL_LIB_FOR_DIRECT_XIP