brcmfmac: Use consistent naming for BCDC.

The BCDC protocol layer is using a mix of naming of CDC, BDC and
BCDC. Use the name BCDC consistenly over all functions, defines
and variables. This patch does not change code functionality.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>