b43: implement baseband init for LP-PHY <= rev1

Implement baseband init for rev.0 and rev.1 LP PHYs. Convert boardflags_hi values to defines.
Implement b43_phy_copy for easier copying between registers, as needed by LP-PHY init.

Signed-off-by: Gábor Stefanik<netrolller.3d@gmail.com>
Cc: Michael Buesch<mb@bu3sch.de>
Cc: Larry Finger<larry.finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>