chip/mt_scp: move video encode/decode IRQ to group 8
chip/mt_scp: move video encode/decode IRQ to group 8

The IRQ triggering frequency of video encode/decode IRQ is propotional
to frame rate. Assign these IRQs with group 8 to prevent blocking IPI
IRQ handler (group 7).

BRANCH=none
BUG=b:189300514
TEST=make BOARD=cherry_scp

Change-Id: Iab7147fbecc02217656bef1493574461ad54cb29
Signed-off-by: Tinghan Shen <c9ff063c8de5b2a8e3ffacf80169ee51e722b470@mediatek.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3010781
Reviewed-by: Tzung-Bi Shih <5e6f7578cd434ae5b4c9ffe5250f7a87a25045d7@chromium.org>
Commit-Queue: Tzung-Bi Shih <5e6f7578cd434ae5b4c9ffe5250f7a87a25045d7@chromium.org>
Tested-by: Tzung-Bi Shih <5e6f7578cd434ae5b4c9ffe5250f7a87a25045d7@chromium.org>

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