kbuild/make.cross: reuse setup_cross_vars in setup clang

There is something inconsistent between the make.cross tool and the
production env, so we follow the production env for now. We can further
adjust it if find any issues on any arch.

Signed-off-by: Yujie Liu <yujie.liu@intel.com>
Signed-off-by: Philip Li <philip.li@intel.com>

kbuild/make.cross

@@ -333,33 +333,9 @@ setup_crosstool_clang()
 	fi
 
 	# TODO: CROSS_COMPILE is not necessary for new kernel
-	if [[ $ARCH = "arm64" ]]; then
-		opt_cross="$opt_cross CROSS_COMPILE=aarch64-linux-gnu-"
-	elif [[ $ARCH = "arm" ]]; then
-		opt_cross="$opt_cross CROSS_COMPILE=arm-linux-gnueabi-"
-	elif [[ $ARCH = "s390" ]]; then
-		opt_cross="$opt_default_cross CROSS_COMPILE=s390x-linux-gnu-"
-	elif [[ $ARCH = "hexagon" ]]; then
-		opt_cross="$opt_cross CROSS_COMPILE=hexagon-linux-"
-	elif [[ $ARCH = "powerpc" ]]; then
-		local cross_compile='powerpc-linux-gnu-'
-		is_config_enabled 'CONFIG_PPC64' && {
-			if is_config_enabled 'CONFIG_CPU_LITTLE_ENDIAN'; then
-				cross_compile='powerpc64le-linux-gnu-'
-			else
-				cross_compile='powerpc64-linux-gnu-'
-			fi
-		}
-		opt_cross="$opt_cross CROSS_COMPILE=$cross_compile"
-	elif [[ $ARCH = "riscv" ]]; then
-		if is_config_enabled 'CONFIG_32BIT'; then
-			opt_cross="$opt_cross $(COMPILER=gcc && setup_crosstool_gcc && echo $opt_cross)"
-		else
-			opt_cross="$opt_cross CROSS_COMPILE=riscv64-linux-gnu-"
-		fi
-	else
-		opt_cross="$opt_cross CROSS_COMPILE=$ARCH-linux-gnu-"
-	fi
+	setup_cross_vars
+	[[ $ARCH = s390 ]] && crosstool=s390x-linux
+	opt_cross="$opt_cross CROSS_COMPILE=$crosstool-"
 
 	local opt_llvm_ias=$(setup_llvm_ias "$opt_cross")
 	[[ $opt_llvm_ias ]] && opt_cross="$opt_cross $opt_llvm_ias"