sh: Revamp PCI DMA coherence Kconfig bits.

Leaving this configurable caused more trouble than it was ever worth, so
just make it explicit. Boards that are verified one way or the other can
fix up their selects accordingly. We presently default to non-coherent
for most platforms.

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

arch/sh/drivers/pci/Kconfig

@@ -5,15 +5,3 @@ config PCI
 	  Find out whether you have a PCI motherboard. PCI is the name of a
 	  bus system, i.e. the way the CPU talks to the other stuff inside
 	  your box. If you have PCI, say Y, otherwise N.
-
-config SH_PCIDMA_NONCOHERENT
-	bool "Cache and PCI noncoherent"
-	depends on PCI
-	default y
-	help
-	  Enable this option if your platform does not have a CPU cache which
-	  remains coherent with PCI DMA. It is safest to say 'Y', although you
-	  will see better performance if you can say 'N', because the PCI DMA
-	  code will not have to flush the CPU's caches. If you have a PCI host
-	  bridge integrated with your SH CPU, refer carefully to the chip specs
-	  to see if you can say 'N' here. Otherwise, leave it as 'Y'.