Remove gdb-ccache-workaround.patch
    
    This patch adds a work around for an issue with older versions of
    ccache -- the line number for macros defined at the compiler command
    line was '1' instead of '0'.
    
    Not only is this ccache issue fixed with newer versions of ccache, but
    upstream GDB now disables ccache during testing, see commit:
    
      commit 49b4de64242d4ae035e0e2197837278e33c187fc
      Date:   Thu Sep 15 14:04:20 2016 +0200
    
          testsuite: Disable ccache
    
    As a result this work around is no longer needed, and this patch can
    be dropped.