wifi: iwlwifi: Separate loading and setting of power reduce tables

Take the part that copies the tables into DRAM, out of the method
that sets the prph_scratch to make the code cleaner. Each of the
operations will get more complex in the future when it will also
support larger power-reduce tables images.

Signed-off-by: Alon Giladi <alon.giladi@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230606103519.7695684dc848.I13626cd318e5d68efec9618b2045f52788bff114@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>