Allow Gen version decimals.
Allow Gen version decimals.

This is preparatory work for Haswell (Gen 7.5).

Signed-off-by: Gwenole Beauchesne <729713629d9640cc095f1c77c692e1881f8093c4@intel.com>

freedesktop-unofficial-mirror/xorg__app__intel-gen4asm,freedesktop-unofficial-mirror/xorg__app__intel-gen4asm