debug/gdb: update Linaro GDB revisions to 2012.04

Update Linaro GDB with the latest available revisions.

Signed-off-by: "Benoît Thébaudeau" <benoit.thebaudeau@advansee.com>

reporter_name="Gustavo Zacarias <gustavo@zacarias.com.ar>"

reporter_url="http://sourceware.org/ml/crossgcc/2011-03/msg00028.html"

reporter_comment=""