Respect libdir for install path

Distritubions may install libraries under architecture-specific
sub-directories, to support multiple architectures on the same
system. In addition, the user may not wish to install the library
with the default prefix.

Use the libdir variable when setting the install path. This
allows both specifying different sub-directories, and a different
prefix.

src/meson.build

@@ -85,7 +85,7 @@ deps = [
 v4l2_request_drv_video = shared_module('v4l2_request_drv_video',
 	name_prefix: '',
 	install: true,
-	install_dir: '/usr/lib/dri/',
+	install_dir: join_paths(get_option('libdir'), 'dri'),
 	c_args: cflags,
 	sources: [ sources, headers, autoconf ],
 	include_directories: includes,