brcmfmac: support hardware extension header in trace_brcmf_sdpcm_hdr()

The SDPCM header can be traced, but it used a fixed header size. With
txglom feature the SDPCM header will have additional 8 bytes of hardware
extension header so SDIO core can properly handle the txglom packet.

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