Driver Core: Increase the default timeout value of the firmware subsystem

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=174589

The ipw driver sometimes takes a long time to load its firmware.
Whilst the ipw driver should be using the async interface of
the firmware loader to make this a non-issue, this is a minimal fix.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>