Patch merged into coreboot/master: 0748d30 boot state: add ability to block state transitions

the following patch was just integrated into master:
commit 0748d305545440ae89034542ea761d39b9aab526
Author: Aaron Durbin 
Date:   Mon May 6 10:50:19 2013 -0500

boot state: add ability to block state transitions

In order to properly sequence the boot state machine it's
    important that outside code can block the transition from
    one state to the next. When timers are not involved there's
    no reason for any of the existing code to block a state
    transition. However, if there is a timer callback that needs to
    complete by a certain point in the boot sequence it is necessary
    to place a block for the given state.

To that end, 4 new functions are added to provide the API for
    blocking a state.
    1. boot_state_block(boot_state_t state, boot_state_sequence_t seq);
    2. boot_state_unblock(boot_state_t state, boot_state_sequence_t seq);
    3. boot_state_current_block(void);
    4. boot_state_current_unblock(void);

Change-Id: Ieb37050ff652fd85a6b1e0e2f81a1a2807bab8e0
    Signed-off-by: Aaron Durbin 
    Reviewed-on: http://review.coreboot.org/3204
    Tested-by: build bot (Jenkins)
    Reviewed-by: Paul Menzel 
    Reviewed-by: Stefan Reinauer

Build-Tested: build bot (Jenkins) at Tue May  7 10:23:05 2013, giving +1
Reviewed-By: Stefan Reinauer  at Tue May  7 20:07:42 2013, giving +2
See http://review.coreboot.org/3204 for details.

-gerrit