configure: add support for 74kf cpu

Signed-off-by: Shivraj Patil <shivraj.patil@imgtec.com>
Reviewed-by: Nedeljko Babic <Nedeljko.Babic@imgtec.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

configure

@@ -3884,6 +3884,11 @@ elif enabled mips; then
             disable mipsfpu
             disable msa
         ;;
+        74kf)
+            disable mips32r5
+            disable mips64r6
+            disable msa
+        ;;
         p5600)
             disable mips64r6
             disable mipsdspr1