debug/gdb: update Linaro GDB revisions to 2012.12-1

Update Linaro GDB with the latest available revisions.

Signed-off-by: "Benoît Thébaudeau" <benoit.thebaudeau@advansee.com>
Message-Id: <b6c4a82286f9a3de3948.1355761104@advdt005-ubuntu>
Patchwork-Id: 206907

 This is NOT the official version of dialog.  This version has been

 significantly modified from the original.  It is for use by the Linux

 kernel configuration script.  Please do not bother Savio Lam with 

 questions about this program.