smc91x: pass along private data V2

Pass a private data pointer to macros and functions. This makes it easy
to later on make run time decisions. This patch does not change any logic.
These changes should be optimized away during compilation.

V2 changes the macro argument name from "priv" to "lp".

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>