meson: gallium media state trackers require libdrm with x11

v2: - update copyright year in all changed files
    - rebase on master

Cc: 19.1 19.2 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
diff --git a/meson.build b/meson.build
index aea5c2e..9fe017d 100644
--- a/meson.build
+++ b/meson.build
@@ -1445,6 +1445,9 @@
         with_gallium_omx != 'disabled'))
     dep_xcb = dependency('xcb')
     dep_x11_xcb = dependency('x11-xcb')
+    if not dep_libdrm.found()
+      error('libdrm required for gallium video statetrackers when using x11')
+    endif
   endif
   if with_any_vk or with_egl or (with_glx == 'dri' and with_dri_platform == 'drm')
     dep_xcb_dri2 = dependency('xcb-dri2', version : '>= 1.8')