brcm80211: smac: change buffer endianess convert function interface

The buffer endianess conversion functions in srom.c had a size
argument giving number of bytes but the function converts words.
Providing the number of words to the function is more sensible
so that is done in this patch.

Reported-by: Pavel Roskin <proski@gnu.org>
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Alwin Beukers <alwin@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>