set TC3 ARCH_FLASH_OFFSET with ?=

Author: bigbrett

arch.mk

@@ -1568,7 +1568,7 @@ ifeq ($(ARCH), AURIX_TC3)
     endif
 
     ifeq ($(AURIX_TC3_HSM),1)
-      ARCH_FLASH_OFFSET=0x80028000
+      ARCH_FLASH_OFFSET?=0x80028000
       # HSM compiler flags, build options, source code, etc
       ifeq ($(USE_GCC),1)
         # Just arm-none-eabi-gcc for now
@@ -1635,7 +1635,7 @@ ifeq ($(ARCH), AURIX_TC3)
 
     else
       # Tricore compiler settings
-      ARCH_FLASH_OFFSET=0x800A0000
+      ARCH_FLASH_OFFSET?=0x800A0000
       ifeq ($(USE_GCC),1)
         HT_ROOT?=/opt/hightec/gnutri_v4.9.4.1-11fcedf-lin64
         CROSS_COMPILE?=$(HT_ROOT)/bin/tricore-