[MIPS] Make ioremap() work on TX39/49 special unmapped segment

TX39XX and TX49XX have "reserved" segment in CKSEG3 area.
0xff000000-0xff3fffff on TX49XX and 0xff000000-0xfffeffff on TX39XX
are reserved (unmapped, uncached).  Controllers on these SoCs are
placed in this segment.

This patch add plat_ioremap() and plat_iounmap() to override default
behavior and implement these hooks for TX39/TX49.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 2b9af2f..96d4abb 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -580,6 +580,7 @@
 #
 core-$(CONFIG_TOSHIBA_RBTX4927)	+= arch/mips/tx4927/toshiba_rbtx4927/
 core-$(CONFIG_TOSHIBA_RBTX4927)	+= arch/mips/tx4927/common/
+cflags-$(CONFIG_TOSHIBA_RBTX4927) += -Iinclude/asm-mips/mach-tx49xx
 load-$(CONFIG_TOSHIBA_RBTX4927)	+= 0xffffffff80020000
 
 #
@@ -587,6 +588,7 @@
 #
 core-$(CONFIG_TOSHIBA_RBTX4938) += arch/mips/tx4938/toshiba_rbtx4938/
 core-$(CONFIG_TOSHIBA_RBTX4938) += arch/mips/tx4938/common/
+cflags-$(CONFIG_TOSHIBA_RBTX4938) += -Iinclude/asm-mips/mach-tx49xx
 load-$(CONFIG_TOSHIBA_RBTX4938) += 0xffffffff80100000
 
 cflags-y			+= -Iinclude/asm-mips/mach-generic