On spatial multiplexing power save in rtlwifi (rtl8192de)

[Dmitry Antipov <dmantipov@xxxxxxxxx>]

Shouldn't 'rtl92de_update_hal_rate_table()' avoid hardcoded 'mimo_ps'
but rather extract it from 'struct rtl_sta_info' like it's done in
'rtl92de_update_hal_rate_mask()'?

Dmitry