mei: avoid FW version request on Ibex Peak and earlier

The fixed MKHI client on PCH 6 gen platforms
does not support fw version retrieval.
The error is not fatal, but it fills up the kernel logs and
slows down the driver start.
This patch disables requesting FW version on GEN6 and earlier platforms.

Fixes warning:
[   15.964298] mei mei::55213584-9a29-4916-badf-0fb7ed682aeb:01: Could not read FW version
[   15.964301] mei mei::55213584-9a29-4916-badf-0fb7ed682aeb:01: version command failed -5

Cc: <stable@vger.kernel.org> +v4.18
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20191004181722.31374-1-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>