Revert "vl: Enable DRM by default."

Reason:

meson.build:586:7: ERROR: Unknown variable "dep_libdrm".

if building without x11 platform.

This reverts commit 392c60928a.

meson.build

@@ -589,9 +589,9 @@ if not system_has_kms_drm
   else
     _va = 'false'
   endif
-elif not (with_platform_x11 or dep_libdrm.found())
+elif not (with_platform_x11 or with_platform_drm)
   if _va == 'true'
-    error('VA state tracker requires X11 platform support or libdrm.')
+    error('VA state tracker requires X11 or drm or wayland platform support.')
   else
     _va = 'false'
   endif

src/gallium/auxiliary/meson.build

@@ -490,7 +490,7 @@ if with_dri2 and with_platform_x11
     files_libgalliumvlwinsys += files('vl/vl_winsys_dri3.c')
   endif
 endif
-if dep_libdrm.found()
+if with_platform_drm
   files_libgalliumvlwinsys += files('vl/vl_winsys_drm.c')
 endif
 

src/gallium/auxiliary/vl/vl_winsys.h

@@ -92,7 +92,7 @@ static inline struct vl_screen *
 vl_dri3_screen_create(void *display, int screen) { return NULL; };
 #endif
 
-#ifdef HAVE_LIBDRM
+#ifdef HAVE_DRM_PLATFORM
 struct vl_screen *
 vl_drm_screen_create(int fd);
 #else