meson: wayland: move dep checks to the lib

Moves them closer to where they are used.  We don't want every check in
the main meson.build file.

gst-libs/gst/meson.build

@@ -10,7 +10,5 @@ subdir('interfaces')
 subdir('mpegts')
 subdir('player')
 subdir('video')
-if use_wayland
 subdir('wayland')
-endif
 subdir('gl')

gst-libs/gst/wayland/meson.build

@@ -1,3 +1,12 @@
+wl_req = '>= 1.4'
+wl_client_dep = dependency('wayland-client', version: wl_req, required: false)
+libdrm_dep = dependency('libdrm', version: '>= 2.4.55', required: false)
+wl_protocol_dep = dependency('wayland-protocols', version: wl_req,
+                             required: false)
+wl_scanner = find_program('wayland-scanner')
+use_wayland = wl_protocol_dep.found() and wl_client_dep.found() and wl_scanner.found() and libdrm_dep.found()
+
+if use_wayland
   gstwayland = library('gstwayland-' + api_version,
     'wayland.c',
     c_args : gst_plugins_bad_args + ['-DGST_USE_UNSTABLE_API'],
@@ -11,3 +20,4 @@ gstwayland = library('gstwayland-' + api_version,
   gstwayland_dep = declare_dependency(link_with : gstwayland,
     include_directories : [libsinc],
     dependencies : [gst_dep, gstvideo_dep])
+endif

meson.build

@@ -331,16 +331,6 @@ else
   cdata.set('DISABLE_ORC', 1)
 endif
 
-# Wayland checks
-
-wl_req = '>= 1.4'
-wl_client_dep = dependency('wayland-client', version: wl_req, required: false)
-libdrm_dep = dependency('libdrm', version: '>= 2.4.55', required: false)
-wl_protocol_dep = dependency('wayland-protocols', version: wl_req,
-                             required: false)
-wl_scanner = find_program('wayland-scanner')
-use_wayland = wl_protocol_dep.found() and wl_client_dep.found() and wl_scanner.found() and libdrm_dep.found()
-
 configure_file(input : 'config.h.meson',
   output : 'config.h',
   configuration : cdata)