add IAR support for G0 with cmake

hw/bsp/imxrt/family.cmake

@@ -53,7 +53,7 @@ if (NOT TARGET ${BOARD_TARGET})
   update_board(${BOARD_TARGET})
 
   if (NOT DEFINED LD_FILE_${TOOLCHAIN})
-    set(LD_FILE_gcc ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/${MCU_VARIANT}xxxxx_flexspi_nor.ld)
+    set(LD_FILE_GCC ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/${MCU_VARIANT}xxxxx_flexspi_nor.ld)
   endif ()
 
   if (TOOLCHAIN STREQUAL "gcc")
@@ -61,7 +61,7 @@ if (NOT TARGET ${BOARD_TARGET})
       ${SDK_DIR}/devices/${MCU_VARIANT}/gcc/startup_${MCU_VARIANT}.S
       )
     target_link_options(${BOARD_TARGET} PUBLIC
-      "LINKER:--script=${LD_FILE_gcc}"
+      "LINKER:--script=${LD_FILE_GCC}"
       # nanolib
       --specs=nosys.specs
       --specs=nano.specs