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/drivers/usb/ehci_debug.c

@@ -382,7 +382,7 @@ static int ehci_reset_port(struct ehci_regs *ehci_regs, int port)
 	u32 portsc;
 	int loop;
 
-	/* Reset the usb debug port */
+	/* Reset the USB debug port */
 	portsc = read32(&ehci_regs->port_status[port - 1]);
 	portsc &= ~PORT_PE;
 	portsc |= PORT_RESET;