debug/gdb: update Linaro GDB revisions to 2012.09

Update Linaro GDB with the latest available revisions.

Signed-off-by: "Benoît Thébaudeau" <benoit.thebaudeau@advansee.com>
Message-Id: <100d9c4f4fb2aeab2a57.1348236919@advdt005-ubuntu>
PatchWork-ID: 185742

# Compute Alpha-specific values

CT_DoArchTupleValues () {

    # The architecture part of the tuple:

    CT_TARGET_ARCH="${CT_ARCH}${CT_ARCH_ALPHA_VARIANT}"

}