treewide: capitalize 'USB'

Change-Id: I7650786ea50465a4c2d11de948fdb81f4e509772
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39100
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/mediatek/common/usb.c

@@ -104,7 +104,7 @@ static int check_ip_clk_status(void)
 
 	do {
 		if (stopwatch_expired(&sw)) {
-			u3p_err("usb clocks are not stable!!!\n");
+			u3p_err("USB clocks are not stable!!!\n");
 			return -1;
 		}