MIPS: cpu-features: Add cpu_has_ftlb

Add cpu_has_ftlb, which specifies that an FTLB is present in addition to
the VTLB, probed based on whether Config.MT == 4 (rather than 1 for
standard JTLB).

This is necessary since MIPS release 6 removes Config4.MMUExtDef, so the
presence of the FTLB fields in Config4 must be determined from Config.MT
instead.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11159/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index d3cd8ea..c64781c 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -487,6 +487,8 @@
 
 /* Bits specific to the MIPS32/64 PRA.	*/
 #define MIPS_CONF_MT		(_ULCAST_(7) <<	 7)
+#define MIPS_CONF_MT_TLB	(_ULCAST_(1) <<  7)
+#define MIPS_CONF_MT_FTLB	(_ULCAST_(4) <<  7)
 #define MIPS_CONF_AR		(_ULCAST_(7) << 10)
 #define MIPS_CONF_AT		(_ULCAST_(3) << 13)
 #define MIPS_CONF_M		(_ULCAST_(1) << 31)