[NET] smc91x: add SMC91X_NOWAIT flag to platform data

And also favors the usage of SMC91X_NOWAIT over the hardcoded SMC_NOWAIT
by converting "nowait" (module parameter overridable) to platform flag.

There are several possibilities:

  1. platform data present - preferred and use as is
  2. platform data absent  - use "nowait", it can be:
       a. SMC_NOWAIT if defined
       b. default to 0 if SMC_NOWAIT isn't defined
       c. overriden by module parameter

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>