ANDROID: arm64: vdso32: fix CC=clang build

clang build had wrong --gcc-toolchain for cross compiler.

Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 63737556
Change-Id: Ib0c3bbb250943a0309da021ba5335a8320b584f4
Signed-off-by: SirRGB <sirrgb@proton.me>

arch/arm64/kernel/vdso32/Makefile

@@ -6,6 +6,10 @@
 
 ifeq ($(cc-name),clang)
   CC_ARM32 := $(CC) $(CLANG_TARGET_ARM32) -no-integrated-as $(CLANG_GCC32_TC) $(CLANG_PREFIX32)
+  GCC_ARM32_TC := $(realpath $(dir $(shell which $(CROSS_COMPILE_ARM32)ld))/..)
+ifneq ($(GCC_ARM32_TC),)
+  CC_ARM32 += --gcc-toolchain=$(GCC_ARM32_TC)
+endif
 else
   CC_ARM32 := $(CROSS_COMPILE_COMPAT)$(cc-name)
 endif
@@ -29,7 +33,9 @@ cc32-ldoption = $(call try-run,\
 # NOSTDINC_FLAGS
 VDSO_CPPFLAGS := -nostdinc -isystem $(shell $(CC_ARM32) -print-file-name=include)
 VDSO_CPPFLAGS += $(LINUXINCLUDE)
-VDSO_CPPFLAGS += $(KBUILD_CPPFLAGS)
+VDSO_CPPFLAGS += -D__KERNEL__
+VDSO_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
+VDSO_CPPFLAGS += $(ARCH_CPPFLAGS) $(KCPPFLAGS)
 
 # Common C and assembly flags
 # From top-level Makefile