mb/hp/revolve_810_g1: Don't clear BUC and beyond

The BUC register is actually 8 bits wide and shouldn't be bluntly
cleared.

Change-Id: I2ffd2d161005e839e730102b56af4f66efeb551e
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36892
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/mainboard/hp/revolve_810_g1/early_init.c

@@ -25,11 +25,6 @@
 #include <southbridge/intel/bd82x6x/pch.h>
 #include <ec/hp/kbc1126/ec.h>
 
-void mainboard_late_rcba_config(void)
-{
-	RCBA32(BUC) = 0x00000000;
-}
-
 const struct southbridge_usb_port mainboard_usb_ports[] = {
 	{ 1, 1, 0 },
 	{ 1, 0, 0 },