drm: small cleanups

This patch contains the following small cleanups:
- make two needlessly global functions static
- drm_sysfs.c: every file should #include the header with the prototypes
              of the global functions it is offering

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dave Airlie <airlied@linux.ie>

drivers/char/drm/drm_context.c

@@ -308,7 +308,7 @@ found:
  *
  * Attempt to set drm_device::context_flag.
  */
-int drm_context_switch( drm_device_t *dev, int old, int new )
+static int drm_context_switch( drm_device_t *dev, int old, int new )
 {
         if ( test_and_set_bit( 0, &dev->context_flag ) ) {
                 DRM_ERROR( "Reentering -- FIXME\n" );