wifi: Enable appropriate clock for qrd8930

The 48 MHz clock is not being enabled for 8930 QRD devices.  Set the
has48MHz_xo variable to '0' if the device does not support 48 MHz
clock, so that it would use 19.2 MHz clock. For QRD devices which
support 48MHz clock, set this variable to '1'.

Change-Id: If72d14f8e26944ae33cbad5079ccf07c3fb2787c
CRs-fixed: 477042
Signed-off-by: Jeff Johnson <jjohnson@codeaurora.org>