drop MOD_INVALID, MOD_LINEAR definitions

MOD_INVALID came with libdrm 2.4.83 and MOD_LINEAR came with libdrm
2.4.82. libweston unconditionally depends on libdrm >= 2.4.95, so the
fallback is not necessary.

Since linux-dmabuf.h itself has no use for these and also forgets to
include drm_fourcc.h, .c files including drm_fourcc.h after this header
would trigger compiler warnings.

linux-dmabuf.c does need these, so add the proper include.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

clients/simple-dmabuf-egl.c

@@ -60,10 +60,6 @@
 
 #include "shared/weston-egl-ext.h"
 
-#ifndef DRM_FORMAT_MOD_INVALID
-#define DRM_FORMAT_MOD_INVALID ((1ULL << 56) - 1)
-#endif
-
 /* Possible options that affect the displayed image */
 #define OPT_IMMEDIATE     (1 << 0)  /* create wl_buffer immediately */
 #define OPT_IMPLICIT_SYNC (1 << 1)  /* force implicit sync */

libweston/backend-drm/kms.c

@@ -42,10 +42,6 @@
 #include "pixel-formats.h"
 #include "presentation-time-server-protocol.h"
 
-#ifndef DRM_FORMAT_MOD_LINEAR
-#define DRM_FORMAT_MOD_LINEAR 0
-#endif
-
 struct drm_property_enum_info plane_type_enums[] = {
 	[WDRM_PLANE_TYPE_PRIMARY] = {
 		.name = "Primary",

libweston/linux-dmabuf.c

@@ -30,6 +30,8 @@
 #include <unistd.h>
 #include <sys/types.h>
 
+#include <drm_fourcc.h>
+
 #include <libweston/libweston.h>
 #include "linux-dmabuf.h"
 #include "linux-dmabuf-unstable-v1-server-protocol.h"

libweston/linux-dmabuf.h

@@ -29,12 +29,6 @@
 #include <stdint.h>
 
 #define MAX_DMABUF_PLANES 4
-#ifndef DRM_FORMAT_MOD_INVALID
-#define DRM_FORMAT_MOD_INVALID ((1ULL<<56) - 1)
-#endif
-#ifndef DRM_FORMAT_MOD_LINEAR
-#define DRM_FORMAT_MOD_LINEAR 0
-#endif
 
 struct linux_dmabuf_buffer;
 typedef void (*dmabuf_user_data_destroy_func)(