sh: Kill off cf-enabler with extreme prejudice.

Now that the rest of the boards that were using cf-enabler "generically"
have switched to setting up their mappings on their own, only the mach-se
boards were left using it. All of the cf-enabler using mach-se boards
use a special initialization of the MRSHPC windows rather than going
through the special PTE as other SH-4 platforms do. This consolidates
the MRSHPC setup logic, hooks it up on the boards that care, and gets rid
of any and all remaining references to cf-enabler.

This has been long overdue, as cf-enabler has been the bane of
arch/sh/kernel for the last 7 years. Good riddance.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>