AP_HAL_ChibiOS: entirely remove check_limit_flash_1M if not needed

taking up valuable space on non-F427 boards

Tools/AP_Bootloader/AP_Bootloader.cpp

@@ -62,9 +62,11 @@ AP_FlashIface_JEDEC ext_flash;
 
 int main(void)
 {
+#ifdef STM32F427xx
     if (BOARD_FLASH_SIZE > 1024 && check_limit_flash_1M()) {
         board_info.fw_size = (1024 - (FLASH_BOOTLOADER_LOAD_KB + APP_START_OFFSET_KB))*1024;
     }
+#endif
 
     bool try_boot = false;
     uint32_t timeout = HAL_BOOTLOADER_TIMEOUT;

libraries/AP_HAL_ChibiOS/hwdef/common/stm32_util.c

@@ -565,9 +565,9 @@ unsigned int stm32_rand_generate_nonblocking(unsigned char* output, unsigned int
 /*
   see if we should limit flash to 1M on devices with older revisions of STM32F427
  */
+#ifdef STM32F427xx
 bool check_limit_flash_1M(void)
 {
-#ifdef STM32F427xx
     const uint16_t revid = (*(uint32_t *)DBGMCU_BASE) >> 16;
     static const uint16_t badrevs[4] = { 0x1000, 0x1001, 0x1003, 0x1007 };
     for (uint8_t i=0; i<4; i++) {
@@ -575,6 +575,6 @@ bool check_limit_flash_1M(void)
             return true;
         }
     }
-#endif
     return false;
 }
+#endif