drm/i915: Make some string arrays const

Most of our char* arrays are markes as const already, but a few slipped
through the cracks. Fix it.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_sdvo.c

@@ -53,7 +53,7 @@
 #define IS_DIGITAL(c) (c->output_flag & (SDVO_TMDS_MASK | SDVO_LVDS_MASK))
 
 
-static const char *tv_format_names[] = {
+static const char * const tv_format_names[] = {
 	"NTSC_M"   , "NTSC_J"  , "NTSC_443",
 	"PAL_B"    , "PAL_D"   , "PAL_G"   ,
 	"PAL_H"    , "PAL_I"   , "PAL_M"   ,
@@ -452,7 +452,7 @@ static void intel_sdvo_debug_write(struct intel_sdvo *intel_sdvo, u8 cmd,
 	DRM_DEBUG_KMS("%s: W: %02X %s\n", SDVO_NAME(intel_sdvo), cmd, buffer);
 }
 
-static const char *cmd_status_names[] = {
+static const char * const cmd_status_names[] = {
 	"Power on",
 	"Success",
 	"Not supported",