android: vulkan: add support for libmesa_vulkan_util

The following changes are implemented:

Add src/vulkan/Android.mk to build libmesa_vulkan_util
Android.mk: add src/vulkan to SUBDIR to build new module
intel/vulkan: fix libmesa_vulkan_util,vk_enum_to_str.h dependencies
Add -o OUTPUT_PATH option in src/vulkan/util/gen_enum_to_str.py script
Use -o OUTPUT_PATH option in automake generation rules for vk_enum_to_str.{c,h}

Fixes: e9dcb17 "vulkan/util: Add generator for enum_to_str functions"
Fixes: 8e03250 "vulkan: Combine wsi and util makefiles"
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

[Emil Velikov]
 - Move parser within main()
 - Use --outdir instead of -o
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
diff --git a/Android.mk b/Android.mk
index 33f1d14..9afa415 100644
--- a/Android.mk
+++ b/Android.mk
@@ -97,7 +97,8 @@
 	src/egl \
 	src/amd \
 	src/intel \
-	src/mesa/drivers/dri
+	src/mesa/drivers/dri \
+	src/vulkan
 
 INC_DIRS := $(call all-named-subdir-makefiles,$(SUBDIRS))