Conditionally build texfat.ko module

Build the module only when TARGET_GENERATE_TEXFAT flag is set
to true.

Issue: FP3-A11#46
Change-Id: I4da79fc15db45ba7347464e21b4234e4895ddbd4
(cherry picked from commit 69f9a331584339a4f576ba33d8459c700d710b7b)
diff --git a/AndroidKernel.mk b/AndroidKernel.mk
index 35726c3..b61f13e 100644
--- a/AndroidKernel.mk
+++ b/AndroidKernel.mk
@@ -213,7 +213,26 @@
 			echo $(KERNEL_CONFIG_OVERRIDE) >> $(KERNEL_OUT)/.config; \
 			$(MAKE) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) CROSS_COMPILE=$(KERNEL_CROSS_COMPILE) $(real_cc) oldconfig; fi
 
+ifeq ($(TARGET_GENERATE_TEXFAT), true)
+# Pull in the texfat kernel module build macros
+include vendor/tuxera/texfat.mk
+endif
+
 ifeq ($(TARGET_KERNEL_APPEND_DTB), true)
+ifeq ($(TARGET_GENERATE_TEXFAT), true)
+TARGET_PREBUILT_INT_KERNEL_IMAGE := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/Image
+$(TARGET_PREBUILT_INT_KERNEL_IMAGE): $(KERNEL_USR)
+$(TARGET_PREBUILT_INT_KERNEL_IMAGE): $(KERNEL_OUT) $(KERNEL_HEADERS_INSTALL)
+	$(hide) echo "Building kernel modules..."
+	$(PATH_OVERRIDE) $(KERNEL_MAKE_CMD) $(KERNEL_MAKE_FLAGS) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) $(KERNEL_LD)  Image
+	$(PATH_OVERRIDE) $(KERNEL_MAKE_CMD) $(KERNEL_MAKE_FLAGS) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) $(KERNEL_LD)  modules
+	$(PATH_OVERRIDE) $(KERNEL_MAKE_CMD) $(KERNEL_MAKE_FLAGS) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) INSTALL_MOD_PATH=$(BUILD_ROOT_LOC)../$(KERNEL_MODULES_INSTALL) INSTALL_MOD_STRIP=1 $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) $(KERNEL_LD)  modules_install
+	$(mv-modules)
+	$(clean-up-texfat)
+	$(generate-texfat)
+	$(extract-texfat)
+	$(clean-module-folder)
+else
 TARGET_PREBUILT_INT_KERNEL_IMAGE := $(KERNEL_OUT)/arch/$(KERNEL_ARCH)/boot/Image
 $(TARGET_PREBUILT_INT_KERNEL_IMAGE): $(KERNEL_USR)
 $(TARGET_PREBUILT_INT_KERNEL_IMAGE): $(KERNEL_OUT) $(KERNEL_HEADERS_INSTALL)
@@ -223,6 +242,7 @@
 	$(PATH_OVERRIDE) $(KERNEL_MAKE_CMD) $(KERNEL_MAKE_FLAGS) -C $(TARGET_KERNEL_SOURCE) O=$(BUILD_ROOT_LOC)$(KERNEL_OUT) INSTALL_MOD_PATH=$(BUILD_ROOT_LOC)../$(KERNEL_MODULES_INSTALL) INSTALL_MOD_STRIP=1 $(KERNEL_MAKE_ENV) ARCH=$(KERNEL_ARCH) $(KERNEL_CROSS_COMPILE) $(KERNEL_CLANG_TRIPLE) $(KERNEL_CC) $(KERNEL_LD)  modules_install
 	$(mv-modules)
 	$(clean-module-folder)
+endif
 
 $(TARGET_PREBUILT_INT_KERNEL): $(TARGET_PREBUILT_INT_KERNEL_IMAGE)
 	$(hide) echo "Building kernel..."