src/soc/tigerlake: Update SerialIoDebugMode UPD in FSP-M

src/soc/tigerlake: Update SerialIoDebugMode UPD in FSP-M

Due to refactoring of Serial IO code in FSP v3163 onwards we need to
set SerialIoUartDebugMode UPD in FSP-M to SkipInit so that SerialIoUart
initialization is skipped in FSP. This makes sure that SerialIo
initialization in coreboot is not changed by FSP.

BUG=b:155315876
BRANCH=none
TEST=build and boot tglrvp/ripto/volteer and check UART debug logs

Cq-Depend: chrome-internal:2944102
Cq-Depend: chrome-internal:2939733
Cq-Depend: chrome-internal:2943140
Signed-off-by: Srinidhi N Kaushik <srinidhi.n.kaushik@intel.com>
Change-Id: I8ba4b9015fa25a84b6b99419ce4d413c9d9daa44
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40899
Reviewed-by: Dossym Nurmukhanov <dossym@google.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>