Added simplified driver setup

If NPU power is guaranteed always on parts of driver setup can be omitted to reduce the number of cycles required to setup the NPU drivers.
By enabling dev_power_always_on, the setup cycles are reduced by approx. ~50%. (4462->2238 in prologue, 1167->642 in epilogue)

Change-Id: I56d380c2571fedbc8888fb7c00fce0e4320f7fb7