ath10k: introduce dynamic WMI structures

This is the initial framework to implement dynamic
WMI API in order to support new firmware (from so
called 10.X branch)

The realization is to have a static WMI cmd map for
each of the firmwares, registered upom wmi init.

This patch creates such map for MAIN FW, updates
wmi_cmd_send() calls to take as a parameter
the map value instead of direct WMI enum.

As soon as complete 10.X API will be on place,
we will introduce the FW IE mechanics to dynamicaly
identify which FW is being used and based on that
we will use correct map, API, structures, etc.

Signed-off-by: Bartosz Markowski <bartosz.markowski@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>