staging: wfx: drop useless structs only used in hif_ind_startup

The structs hif_capabilities, hif_otp_regul_sel_mode_info and
hif_otp_phy_info have no real reasons to exist. Drop them and simplify
access to fields of struct hif_ind_startup.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200907101521.66082-22-Jerome.Pouiller@silabs.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>