staging: rtl8192u: remove checks for CONFIG_RTL8192_PM

When the rtl8192u driver was added in v2.6.33 its code contained checks
for CONFIG_RTL8192_PM. The related Kconfig symbol didn't exist then. It
still doesn't exist now. Remove these checks.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>