i915/gvt: Fix spelling mistake "vender" -> "vendor"

There is a spelling mistake in a literal string. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20230202125018.285523-1-colin.i.king@gmail.com