Documentation: Remove unused "spia_*" kernel parameters

The kernel module parameters "spia_io_base", "spia_fio_base",
"spia_pedr" and "spia_peddr" have been removed via commit e377ca1e
("ARM: clps711x: p720t: Special driver for handling NAND memory is removed").
Time to remove them from the documentation now, too.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240614184041.601056-1-thuth@redhat.com