greenhills: fix the file build path error

Signed-off-by: guoshichao <guoshichao@xiaomi.com>

arch/Kconfig

@@ -288,6 +288,7 @@ config ARCH_TOOLCHAIN_TASKING
 
 config ARCH_TOOLCHAIN_GHS
 	bool
+	select ARCH_TOOLCHAIN_GNU
 	default n
 
 config ARCH_GNU_NO_WEAKFUNCTIONS

arch/arm/src/common/Toolchain.defs

@@ -366,8 +366,10 @@ ZIGFLAGS = -target $(ZARCH)-freestanding-$(ZEABI) $(ZARCHCPUFLAGS)
 
 ifeq ($(CONFIG_ARM_TOOLCHAIN_ARMCLANG),)
   ifeq ($(CONFIG_DEBUG_OPT_UNUSED_SECTIONS),y)
-    LDFLAGS          += --gc-sections
-    ARCHOPTIMIZATION += -ffunction-sections -fdata-sections
+    ifeq ($(CONFIG_ARCH_TOOLCHAIN_GHS),)
+      LDFLAGS          += --gc-sections
+      ARCHOPTIMIZATION += -ffunction-sections -fdata-sections
+    endif
   endif
 endif