drm/i915: Fix GVT-g PVINFO version compatibility check

Current it's strictly checked if PVINFO version matches 1.0
for GVT-g i915 guest which doesn't help for compatibility at
all and forces GVT-g host can't extend PVINFO easily with version
bump for real compatibility check.

This fixes that to check minimal required PVINFO version instead.

v2:
- drop unneeded version macro
- use only major version for sanity check

v3:
- fix up PVInfo value with kernel type
- one indent fix

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chuanxiao Dong <chuanxiao.dong@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170609074805.5101-1-zhenyuw@linux.intel.com