brcmfmac: fix setting AP channel with new firmwares

Firmware for new chipsets is based on a new major version of code
internally maintained at Broadcom. E.g. brcmfmac4366b-pcie.bin (used for
BCM4366B1) is based on 10.10.69.3309 while brcmfmac43602-pcie.ap.bin was
based on 7.35.177.56.

Currently setting AP 5 GHz channel doesn't work reliably with BCM4366B1.
When setting e.g. 36 control channel with VHT80 (center channel 42)
firmware may randomly pick one of:
1) 52 control channel with 58 as center one
2) 100 control channel with 106 as center one
3) 116 control channel with 122 as center one
4) 149 control channel with 155 as center one

It seems new firmwares require setting AP mode (BRCMF_C_SET_AP) before
specifying a channel. Changing an order of firmware calls fixes the
problem. This requirement resulted in two separated "chanspec" calls,
one in AP code path and one in P2P path.

This fix was verified with BCM4366B1 and tested for regressions on
BCM43602.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>