lib: logic_pio: Enforce LOGIC_PIO_INDIRECT region ops are set at registration

Since the only LOGIC_PIO_INDIRECT host (hisi-lpc) now sets the ops prior
to registration, enforce this check for accessors ops at registration
instead of in the IO port accessors to simplify and marginally optimise
the code.

A slight misalignment is also tidied.

Also add myself as an author.

Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>