Add USER_REG3 and indicate it's reserved for preprogramming process data.
Add USER_REG3 and indicate it's reserved for preprogramming process data.

Signed-off-by: Randall Spangler <rspangler@chromium.org>

BUG=chrome-os-partner:8889
TEST=code still builds

Change-Id: Ifdd31189fb5de779f090aa089173407e381c62b7

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