drm/modes: Switch to named mode descriptors

The current named mode parsing relies only on the mode name, and doesn't
allow to specify any other parameter.

Let's convert that string list to an array of a custom structure that will
hold the name and some additional parameters in the future.
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Tested-by: Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>
Link: https://lore.kernel.org/r/20220728-rpi-analog-tv-properties-v9-10-24b168e5bcd5@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/drm_modes.c

@@ -1750,9 +1750,13 @@ static int drm_mode_parse_cmdline_options(const char *str,
 	return 0;
 }
 
-static const char * const drm_named_modes_whitelist[] = {
-	"NTSC",
-	"PAL",
+struct drm_named_mode {
+	const char *name;
+};
+
+static const struct drm_named_mode drm_named_modes[] = {
+	{ "NTSC", },
+	{ "PAL", },
 };
 
 static int drm_mode_parse_cmdline_named_mode(const char *name,
@@ -1784,14 +1788,15 @@ static int drm_mode_parse_cmdline_named_mode(const char *name,
 	 * We're sure we're a named mode at this point, iterate over the
 	 * list of modes we're aware of.
 	 */
-	for (i = 0; i < ARRAY_SIZE(drm_named_modes_whitelist); i++) {
+	for (i = 0; i < ARRAY_SIZE(drm_named_modes); i++) {
+		const struct drm_named_mode *mode = &drm_named_modes[i];
 		int ret;
 
-		ret = str_has_prefix(name, drm_named_modes_whitelist[i]);
+		ret = str_has_prefix(name, mode->name);
 		if (ret != name_end)
 			continue;
 
-		strcpy(cmdline_mode->name, drm_named_modes_whitelist[i]);
+		strcpy(cmdline_mode->name, mode->name);
 		cmdline_mode->specified = true;
 
 		return 1;