intel: Rename Genx keyword to Gfxx

Commands used to do the changes:
export SEARCH_PATH="src/intel src/gallium/drivers/iris src/mesa/drivers/dri/i965"
grep -E "Gen[[:digit:]]+" -rIl $SEARCH_PATH | xargs sed -ie "s/Gen\([[:digit:]]\+\)/Gfx\1/g"

Exclude changes in src/intel/perf/oa-*.xml:
find src/intel/perf -type f \( -name "*.xml" \) | xargs sed -ie "s/Gfx/Gen/g"

Signed-off-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9936>

src/intel/tools/aubinator_viewer_decoder.cpp

@@ -467,7 +467,7 @@ decode_single_ksp(struct aub_viewer_decode_ctx *ctx,
                   const uint32_t *p)
 {
    uint64_t ksp = 0;
-   bool is_simd8 = false; /* vertex shaders on Gen8+ only */
+   bool is_simd8 = false; /* vertex shaders on Gfx8+ only */
    bool is_enabled = true;
 
    struct intel_field_iterator iter;