cr50_rma_open: Disable UART timestamps
cr50_rma_open: Disable UART timestamps

The log timestamps are unexpected by the script, and cause issues.
Send a dut-control command to disable UART timestamps.

Also fix the regex in the board ID portion to accept a colon as well as
a comma, whichever comes first.

BUG=None
TEST=Try cr50_rma_unlock.py
BRANCH=None

Change-Id: Ie9e54e65b86c52aef120fa3249453bfc090cf6f0
Signed-off-by: Evan Green <e00bb247ee1d736884e1d54ef0d6b838cb86c075@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1921703
Reviewed-by: Mary Ruthven <81380f3403fed74252e92df3ed012a1819ec6296@chromium.org>

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