Revert "[Feature][T8TSK-216][system] boot from bl2_b when bl2_a is load fail"

This reverts commit 4917868dcaf4b97bbf210df3f366b6cf276dbcac.

Reason for revert: <INSERT REASONING HERE>

Change-Id: I6419efeb8d7cc167cab76e6c8b1d8d02b865f1da
1 file changed