binutils-cross-canadian.inc: disable -werror like -cross does

    The error this works around is:

    cc1: warnings being treated as errors
    gas/config/tc-arm.c: In function 'parse_operands':
    gas/config/tc-arm.c:1876:27: error: 'firsttype$defined' may be used uninitialized in this function
    gas/config/tc-arm.c:1876:27: error: 'firsttype$index' may be used uninitialized in this function

    Ideally it should get fixed properly, but let's mimic binutils-cross for now

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>