Change UART interrupt to priority 2
Change UART interrupt to priority 2

The UART probably shouldn't have such a high priority. Reduce it to
below that of comms driver interrupts.

BUG=none
BRANCH=none
TEST=manual
Boot and see that UART console still functions

Change-Id: If906c9c4c37617d076ad8415d126b50f52d8b09e
Signed-off-by: Simon Glass <c00b0378376498bd9cd974c388df8854c0131d27@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/32077
Reviewed-by: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>

fourier49/BIZ_EC,akappy7/ChromeOS_EC_LED_Diagnostics,mtk09422/chromiumos-platform-ec,coreboot/chrome-ec,fourier49/BZ_DEV_EC,fourier49/BZ_DEV_EC,eatbyte/chromium-ec,gelraen/cros-ec,eatbyte/chromium-ec,mtk09422/chromiumos-platform-ec,akappy7/ChromeOS_EC_LED_Diagnostics,alterapraxisptyltd/chromium-ec,md5555/ec,thehobn/ec,mtk09422/chromiumos-platform-ec,gelraen/cros-ec,mtk09422/chromiumos-platform-ec,fourier49/BIZ_EC,md5555/ec,md5555/ec,akappy7/ChromeOS_EC_LED_Diagnostics,longsleep/ec,eatbyte/chromium-ec,eatbyte/chromium-ec,fourier49/BIZ_EC,alterapraxisptyltd/chromium-ec,longsleep/ec,alterapraxisptyltd/chromium-ec,akappy7/ChromeOS_EC_LED_Diagnostics,longsleep/ec,md5555/ec,gelraen/cros-ec,thehobn/ec,fourier49/BIZ_EC,thehobn/ec,coreboot/chrome-ec,thehobn/ec,akappy7/ChromeOS_EC_LED_Diagnostics,coreboot/chrome-ec,alterapraxisptyltd/chromium-ec,gelraen/cros-ec,coreboot/chrome-ec,coreboot/chrome-ec,fourier49/BZ_DEV_EC,coreboot/chrome-ec,longsleep/ec,fourier49/BZ_DEV_EC