meson: use dep_libdrm version for pkg-config

This corrects pkg-config to use the libdrm version (as computed by the
previous patch) instead of using a hardcoded value that may or may not
(probably not) be right.

Signed-off-by: Dylan Baker <dylan.c.baker@intel.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>

src/gallium/targets/d3dadapter9/meson.build

@@ -71,6 +71,6 @@ pkg.generate(
   name : 'd3d',
   description : 'Native D3D driver modules',
   version : '.'.join(nine_version),
-  requires_private : 'libdrm >= 2.4.75',
+  requires_private : 'libdrm >= ' + dep_libdrm.version(),
   variables : ['moduledir=${prefix}/@0@'.format(d3d_drivers_path)],
 )

src/mesa/drivers/dri/meson.build

@@ -69,7 +69,7 @@ endif
 if with_dri
   dri_req_private = []
   if dep_libdrm.found()
-    dri_req_private = ['libdrm >= 2.4.75']  # FIXME: don't hardcode this
+    dri_req_private = ['libdrm >= ' + dep_libdrm.version()]
   endif
 
   pkg.generate(