staging: brcm80211: cleanup of several wrapper functions

- removed brcms_c_write_template_ram function.
- removed brcms_c_mctrl function.
- removed brcms_c_pllreq function.
- removed brcms_c_mhf function.
- removed brcms_c_rate_shm_offset function.
- removed brcms_c_write_hw_bcntemplates function.

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>