The boot flags exported through sysfs was wrongly reverted to 2.  Use
boot flag 3 required per spec.

Bit 0 Block valid flag
Bit 1 Firmware booting selected
Signed-off-by: NJitendra Bhivare <jitendra.bhivare@broadcom.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>