mips: do not disable any feature for generic cores

We don't know which features are available when the user selects a
generic core, so don't disable anything by default and let the user
decide.

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

configure

@@ -4258,8 +4258,8 @@ elif enabled mips; then
             esac
         ;;
         generic)
-            disable mips64r6
-            disable msa
+            # We do not disable anything. Is up to the user to disable
+            # the unwanted features.
         ;;
         *)
             # Unknown CPU. Disable everything.