kernel: Add GCC toolchains to the path

Tools like `as` only exist in the GCC toolchain, so we need that

Change-Id: I025d0d9bdf6eda94a538d2d6ddafbecc8830f471
diff --git a/build/tasks/kernel.mk b/build/tasks/kernel.mk
index f4dd92d..a2efcea 100644
--- a/build/tasks/kernel.mk
+++ b/build/tasks/kernel.mk
@@ -169,7 +169,7 @@
         # Use the default version of clang if TARGET_KERNEL_CLANG_VERSION hasn't been set by the device config
         KERNEL_CLANG_VERSION := $(LLVM_PREBUILTS_VERSION)
     endif
-    TARGET_KERNEL_CLANG_PATH ?= $(BUILD_TOP)/prebuilts/clang/host/$(HOST_OS)-x86/$(KERNEL_CLANG_VERSION)/bin
+    TARGET_KERNEL_CLANG_PATH ?= $(BUILD_TOP)/prebuilts/clang/host/$(HOST_OS)-x86/$(KERNEL_CLANG_VERSION)
     ifeq ($(KERNEL_ARCH),arm64)
         KERNEL_CLANG_TRIPLE ?= CLANG_TRIPLE=aarch64-linux-gnu-
     else ifeq ($(KERNEL_ARCH),arm)
@@ -177,7 +177,7 @@
     else ifeq ($(KERNEL_ARCH),x86)
         KERNEL_CLANG_TRIPLE ?= CLANG_TRIPLE=x86_64-linux-gnu-
     endif
-    PATH_OVERRIDE := PATH=$(TARGET_KERNEL_CLANG_PATH):$$PATH LD_LIBRARY_PATH=$(BUILD_TOP)/prebuilts/clang/host/$(HOST_OS)-x86/$(KERNEL_CLANG_VERSION)/lib64:$$LD_LIBRARY_PATH
+    PATH_OVERRIDE := PATH=$(TARGET_KERNEL_CLANG_PATH)/bin:$$PATH LD_LIBRARY_PATH=$(TARGET_KERNEL_CLANG_PATH)/lib64:$$LD_LIBRARY_PATH
     ifeq ($(KERNEL_CC),)
         KERNEL_CC := CC="$(CCACHE_BIN) clang"
     endif
@@ -187,6 +187,8 @@
     TARGET_KERNEL_MODULES := INSTALLED_KERNEL_MODULES
 endif
 
+PATH_OVERRIDE += PATH=$(KERNEL_TOOLCHAIN_PATH_gcc)/bin:$$PATH
+
 # System tools are no longer allowed on 10+
 PATH_OVERRIDE += $(TOOLS_PATH_OVERRIDE)
 
diff --git a/config/BoardConfigKernel.mk b/config/BoardConfigKernel.mk
index 850a413..6958738 100644
--- a/config/BoardConfigKernel.mk
+++ b/config/BoardConfigKernel.mk
@@ -77,6 +77,10 @@
 KERNEL_TOOLCHAIN_PATH := $(KERNEL_TOOLCHAIN)/$(KERNEL_TOOLCHAIN_PREFIX)
 endif
 
+# We need to add GCC toolchain to the path no matter what
+# for tools like `as`
+KERNEL_TOOLCHAIN_PATH_gcc := $(KERNEL_TOOLCHAIN_$(KERNEL_ARCH))/$(KERNEL_TOOLCHAIN_PREFIX_$(KERNEL_ARCH))
+
 ifneq ($(USE_CCACHE),)
     ifneq ($(CCACHE_EXEC),)
         # Android 10+ deprecates use of a build ccache. Only system installed ones are now allowed