UIO: minor Kconfig fixes

Two trivial fixes for the Userspace IO Kconfig file:
1) uio_sercos3 is a PCI driver, so let it depend on PCI.
2) "default n" under UIO_PCI_GENERIC is luxury since it is already the default.

Acked-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>