gpio: crystalcove: support virtual GPIO

The virtual GPIO introduced in ACPI table of Baytrail-T based system is
used to solve a problem under Windows. We do not have such problems
under Linux so we do not actually need them. But we have to tell GPIO
library that the Crystal Cove GPIO chip has this many GPIO pins or the
common GPIO handler will refuse any access to those high number GPIO
pins, which will resulted in a failure evaluation of every ACPI control
method that is used to turn on/off power resource and/or report sensor
temperatures.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[changed vgpio number from 0x5e to 94]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>