intel/dev: use GFX_VERx10 to detect genX compilation

intel/dev: use GFX_VERx10 to detect genX compilation

Depending on the ordering of includes, GFX_VER may not defined for
intel_device_info.h.  The failure mode of this case is silent:
BITSET_TEST will be called when it could be compiled out.

GFX_VERx10 should be used in place of GFX_VER.  GFX_VERx10 is defined
by a compiler flag, and is always present for genX compilation units.

Fixes: 3c9a8f7a6d2 ("intel/dev: generate helpers to identify platform workarounds")
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21908>