MIPS: VDSO: Replace __mips_isa_rev with MIPS_ISA_REV

Remove the need to check that __mips_isa_rev is defined by using the
newly added MIPS_ISA_REV.

Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18678/
Signed-off-by: James Hogan <jhogan@kernel.org>
diff --git a/arch/mips/vdso/elf.S b/arch/mips/vdso/elf.S
index be37bbb..428a191 100644
--- a/arch/mips/vdso/elf.S
+++ b/arch/mips/vdso/elf.S
@@ -10,6 +10,8 @@
 
 #include "vdso.h"
 
+#include <asm/isa-rev.h>
+
 #include <linux/elfnote.h>
 #include <linux/version.h>
 
@@ -40,11 +42,7 @@
 	.byte	__mips		/* isa_level */
 
 	/* isa_rev */
-#ifdef __mips_isa_rev
-	.byte	__mips_isa_rev
-#else
-	.byte	0
-#endif
+	.byte	MIPS_ISA_REV
 
 	/* gpr_size */
 #ifdef __mips64
@@ -54,7 +52,7 @@
 #endif
 
 	/* cpr1_size */
-#if (defined(__mips_isa_rev) && __mips_isa_rev >= 6) || defined(__mips64)
+#if (MIPS_ISA_REV >= 6) || defined(__mips64)
 	.byte	2		/* AFL_REG_64 */
 #else
 	.byte	1		/* AFL_REG_32 */