nct38xx: Add tcpci_nct38xx_select_rp_value
nct38xx: Add tcpci_nct38xx_select_rp_value

nct38xx was using tcpci_nct38xx_set_cc() but this uses selected_rp[]
which was never being set. Add tcpci_nct38xx_select_rp_value() to
set it correctly.

BUG=b:146003980
BRANCH=none
TEST=none

Change-Id: Iaf08b82c41e42f2db233681824b1a36c967fb628
Signed-off-by: Edward Hill <db1406b34e091703092b6b136bdfeb2c8125fc0e@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1960724
Reviewed-by: Denis Brockus <6b21e8190fb5e373363fb95271367073a16474ef@chromium.org>
Commit-Queue: Denis Brockus <6b21e8190fb5e373363fb95271367073a16474ef@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec