stm32/boards: Increase mboot region to 32k for WB55 boards.

If mboot is built with support for packing (signing/encryption) it needs up
to 32KiB.  So for simplicity increase the mboot region to 32KiB
unconditionally for WB55 boards (custom WB55 board configurations can still
provide their own linker scripts to override this).

ports/stm32/boards/NUCLEO_WB55/mpconfigboard.mk

@@ -6,7 +6,7 @@ STARTUP_FILE = $(STM32LIB_CMSIS_BASE)/Source/Templates/gcc/startup_stm32wb55xx_c
 ifeq ($(USE_MBOOT),1)
 # When using Mboot all the text goes together after the bootloader
 LD_FILES = boards/stm32wb55xg.ld boards/common_bl.ld
-TEXT0_ADDR = 0x08004000
+TEXT0_ADDR = 0x08008000
 else
 # When not using Mboot the text goes at the start of flash
 LD_FILES = boards/stm32wb55xg.ld boards/common_basic.ld

ports/stm32/boards/USBDONGLE_WB55/mpconfigboard.mk

@@ -6,7 +6,7 @@ STARTUP_FILE = $(STM32LIB_CMSIS_BASE)/Source/Templates/gcc/startup_stm32wb55xx_c
 ifeq ($(USE_MBOOT),1)
 # When using Mboot all the text goes together after the bootloader
 LD_FILES = boards/stm32wb55xg.ld boards/common_bl.ld
-TEXT0_ADDR = 0x08004000
+TEXT0_ADDR = 0x08008000
 else
 # When not using Mboot the text goes at the start of flash
 LD_FILES = boards/stm32wb55xg.ld boards/common_basic.ld

ports/stm32/boards/stm32wb55xg.ld

@@ -6,7 +6,7 @@
 MEMORY
 {
     FLASH (rx)      : ORIGIN = 0x08000000, LENGTH = 512K /* sectors 0-127 */
-    FLASH_APP (rx)  : ORIGIN = 0x08004000, LENGTH = 496K /* sectors 4-127 */
+    FLASH_APP (rx)  : ORIGIN = 0x08008000, LENGTH = 480K /* sectors 8-127 */
     FLASH_FS (r)    : ORIGIN = 0x08080000, LENGTH = 256K /* sectors 128-191 */
     RAM (xrw)       : ORIGIN = 0x20000000, LENGTH = 192K /* SRAM1 */
     RAM2A (xrw)     : ORIGIN = 0x20030000, LENGTH = 10K  /* SRAM2A */