set_gbb_flags: Aborts only if HW & SW WP are both enabled. Early proto devices (for testers and developers) may have hardware write protection enabled and software disabled. They can still flash SPI ROM in that case, and no need to disable hardware WP switch. BRANCH=none BUG=chromium:341242 TEST=./set_gbb_flags.sh 0x39 # see WP messages. Change-Id: Id320410795a162a009b80360c2225c7510337591 Reviewed-on: https://chromium-review.googlesource.com/186336 Tested-by: Hung-Te Lin <[email protected]> Reviewed-by: Shawn Nematbakhsh <[email protected]> Commit-Queue: Hung-Te Lin <[email protected]> Reviewed-by: Randall Spangler <[email protected]>