kaiser: delete KAISER_REAL_SWITCH option

We fail to see what CONFIG_KAISER_REAL_SWITCH is for: it seems to be
left over from early development, and now just obscures tricky parts
of the code.  Delete it before adding PCIDs, or nokaiser boot option.

(Or if there is some good reason to keep the option, then it needs
a help text - and a "depends on KAISER", so that all those without
KAISER are not asked the question.  But we'd much rather delete it.)

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>