[media] smiapp: Make pixel_order_str static

pixel_order_str is only referred to in smiapp-core.c, it should be thus
static. Thanks to Hans Verkuil for pointing this out.
Signed-off-by: NSakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/i2c/smiapp/smiapp-core.c

@@ -344,7 +344,7 @@ static const struct smiapp_csi_data_format smiapp_csi_data_formats[] = {
 	{ MEDIA_BUS_FMT_SGBRG8_1X8, 8, 8, SMIAPP_PIXEL_ORDER_GBRG, },
 };
 
-const char *pixel_order_str[] = { "GRBG", "RGGB", "BGGR", "GBRG" };
+static const char *pixel_order_str[] = { "GRBG", "RGGB", "BGGR", "GBRG" };
 
 #define to_csi_format_idx(fmt) (((unsigned long)(fmt)			\
 				 - (unsigned long)smiapp_csi_data_formats) \