wifi: brcmfmac: export firmware interface functions

With multi-vendor support the vendor-specific module may need to use
the firmware interface functions so export them using the macro
BRCMF_EXPORT_SYMBOL_GPL() which exports them to driver namespace.

Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240103095704.135651-2-arend.vanspriel@broadcom.com