rtlwifi: Move pr_fmt macros to a single location

Although the rtlwifi family of devices contains 11 copies of the pr_fmt
macro, the macro is not defined for all routines that need it. By moving
the macro to wifi.h, a single copy is available for all routines.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>