boston: Move CM GCRs away from flash

Move the MIPS Coherence Manager (CM) Global Configuration Registers
(GCRs) away from the region of the physical address space which the
Boston board's parallel flash is found in, such that we can access all
of flash without clobbering GCRs.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/mips/Kconfig

@@ -224,6 +224,7 @@ config ROM_EXCEPTION_VECTORS
 config MIPS_CM_BASE
 	hex "MIPS CM GCR Base Address"
 	depends on MIPS_CM
+	default 0x16100000 if TARGET_BOSTON
 	default 0x1fbf8000
 	help
 	  The physical base address at which to map the MIPS Coherence Manager