iwlwifi: add trans_cfg for devices with long latency

iwlwifi: add trans_cfg for devices with long latency

A couple of SoCs, which can be recognized by PCI device IDs 0xA0F0 and
0x43F0, need a longer wait for the xtal to stabilize.  To handle this,
add a new trans_cfg structure for Qu devices with a larger
xtal_latency value and apply them to the devices recognized by these
IDs.  Also add a flag that allows us to inform the FW that the low
latency xtal should be used.

Change-Id: I8a14c6af45ea14d8e7f1ef38a589158f38d0c0ea
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>