brcm80211: Convert log message levels to debug levels

In preparation for enhancements to debug and trace support, convert the
message levels to debug levels which will be used for enabling
categories of debug messages. The two message levels are little-used
anyway and are combined into the BRCM_DL_INFO debug level.

Acked-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Tested-by: Daniel Wagner <wagi@monom.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>