Patch merged into coreboot/master: 1c20e38 libpayload: usb mass storage card hot plug

the following patch was just integrated into master:
commit 1c20e385a09fcbbf83c03b3a2d3713f4403debea
Author: Aaron Durbin 
Date:   Fri Jun 7 12:31:21 2013 -0500

libpayload: usb mass storage card hot plug

Mass storage devices such as card readers show up as
    as USB devices. However the media not be inserted. In those
    situations the previous code would just fake a disk and
    call usbcreate_disk. This is inappropriate because it forms
    a 1:1 mapping of USB device to disk leading to the inability
    to remove the disk and/or handle "hot plug" card insertion
    and removals.

To alleviate this issue introduce the notion of ready to the
    usbmsc structure. It tracks detached, not ready, and ready
    states. The polling routine is then used to track not ready
    to ready transitions thereby creating and removing disks
    appropriately. This handles the case of inserting and removing
    a card that shows up as a new disk.

Booted recovery mode. Able to observe inerstion and removal
    of sdcard. Also able to insert valid USB flash drive to boot
    as well.

Change-Id: I3eefbe537ec1b9c975744b8984b06c17ae236f40
    Signed-off-by: Aaron Durbin 
    Reviewed-on: https://gerrit.chromium.org/gerrit/57948
    Reviewed-by: Duncan Laurie 
    Reviewed-on: http://review.coreboot.org/4226
    Tested-by: build bot (Jenkins)
    Reviewed-by: Ronald G. Minnich

See http://review.coreboot.org/4226 for details.

-gerrit