Remove unused and upstreamed patch
    
    This patch was initially used to fix a bunch of build failures with
    GCC 6. The first hunk was for i386 and x86_64, while the second was for
    ARM. See: https://bugzilla.redhat.com/show_bug.cgi?id=1307280
    
    These have since been upstreamed.
    
    The first hunk was actually not correct because it broke 4-colour RAWs
    with VNG demosaic. So, it was eventually reverted in favour of a better
    patch. See: https://github.com/LibRaw/LibRaw/issues/56
    
    The second hunk was upstreamed as commit f4c0b98581a64147
    
    No need to do a build just for this.