[TC] MIPS: TURBOchannel update to the driver model

This is a set of changes to convert support for the TURBOchannel bus to the
driver model.  It implements the usual set of calls similar to what other bus
drivers have: tc_register_driver(), tc_unregister_driver(), etc.  All the
platform-specific bits have been removed and headers from asm-mips/dec/ have
been merged into linux/tc.h, which should be included by drivers.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>