MIPS: Add CONFIG_CPU_R5500 for NEC VR5500 series processors

We already have sufficient infrastructure to support VR5500 and VR5500A
series processors.  Here's a Makefile support to make it selectable by
ports, and enable it for NEC EMMA2RH Markeins board.

This patch also fixes a confused target help, and adds 1Gb PageMask bits
supported by VR5500 and its variants.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi@necel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 8abac78..a21b12ce 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -131,6 +131,8 @@
 cflags-$(CONFIG_CPU_R5000)	+= -march=r5000 -Wa,--trap
 cflags-$(CONFIG_CPU_R5432)	+= $(call cc-option,-march=r5400,-march=r5000) \
 			-Wa,--trap
+cflags-$(CONFIG_CPU_R5500)	+= $(call cc-option,-march=r5500,-march=r5000) \
+			-Wa,--trap
 cflags-$(CONFIG_CPU_NEVADA)	+= $(call cc-option,-march=rm5200,-march=r5000) \
 			-Wa,--trap
 cflags-$(CONFIG_CPU_RM7000)	+= $(call cc-option,-march=rm7000,-march=r5000) \