aubinator/genxml: use gzipped files to store embedded genxml

This reduces the size of the aubinator binary from ~1.4Mb to ~700Kb.
With can now drop the checks on xxd in configure.

v2: Fix incorrect makefile dependency (Lionel)

v3: use $(PYTHON2) (Emil)

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

configure.ac

@@ -126,7 +126,6 @@ LT_PREREQ([2.2])
 LT_INIT([disable-static])
 
 AC_CHECK_PROG(RM, rm, [rm -f])
-AC_CHECK_PROG(XXD, xxd, [xxd])
 
 AX_PROG_BISON([],
               AS_IF([test ! -f "$srcdir/src/compiler/glsl/glcpp/glcpp-parse.c"],