kernel: Detect kernel module usage better

* Check for any actual kernel modules, rather than just the presence of
  kernel modules being enabled as a kernel feature.

Change-Id: I6b7e82d5c59dd57621d9f9e2d1fd606997790d1c

build/tasks/kernel.mk

@@ -217,7 +217,7 @@ TARGET_KERNEL_BINARIES: $(KERNEL_CONFIG)
 			echo "Building DTBs"; \
 			$(PATH_OVERRIDE) $(MAKE) $(KERNEL_MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) dtbs; \
 		fi
-	$(hide) if grep -q '^CONFIG_MODULES=y' $(KERNEL_CONFIG); then \
+	$(hide) if grep -q '=m' $(KERNEL_CONFIG); then \
 			echo "Building Kernel Modules"; \
 			$(PATH_OVERRIDE) $(MAKE) $(KERNEL_MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) modules; \
 		fi
@@ -227,7 +227,7 @@ INSTALLED_KERNEL_MODULES: depmod-host
 	$(hide) rm -rf $(KERNEL_MODULES_OUT)
 	$(hide) mkdir -p $(KERNEL_MODULES_OUT)
 	$(hide) rm -rf $(KERNEL_DEPMOD_STAGING_DIR)
-	$(hide) if grep -q '^CONFIG_MODULES=y' $(KERNEL_CONFIG); then \
+	$(hide) if grep -q '=m' $(KERNEL_CONFIG); then \
 			echo "Installing Kernel Modules"; \
 			$(PATH_OVERRIDE) $(MAKE) $(KERNEL_MAKE_FLAGS) -C $(KERNEL_SRC) O=$(KERNEL_OUT) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) INSTALL_MOD_PATH=../../$(KERNEL_MODULES_INSTALL) modules_install && \
 			mofile=$$(find $(KERNEL_MODULES_OUT) -type f -name modules.order) && \