[MIPS] Make support for weakly ordered LL/SC a config option.

None of weakly ordered processor supported in tree need this but it seems
like this could change ...

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/bitops.h b/include/asm-mips/bitops.h
index d9e81af..148bc79 100644
--- a/include/asm-mips/bitops.h
+++ b/include/asm-mips/bitops.h
@@ -38,8 +38,8 @@
 /*
  * clear_bit() doesn't provide any barrier for the compiler.
  */
-#define smp_mb__before_clear_bit()	smp_mb()
-#define smp_mb__after_clear_bit()	smp_mb()
+#define smp_mb__before_clear_bit()	smp_llsc_mb()
+#define smp_mb__after_clear_bit()	smp_llsc_mb()
 
 /*
  * set_bit - Atomically set a bit in memory
@@ -289,7 +289,7 @@
 		raw_local_irq_restore(flags);
 	}
 
-	smp_mb();
+	smp_llsc_mb();
 
 	return res != 0;
 }
@@ -377,7 +377,7 @@
 		raw_local_irq_restore(flags);
 	}
 
-	smp_mb();
+	smp_llsc_mb();
 
 	return res != 0;
 }
@@ -445,7 +445,7 @@
 		raw_local_irq_restore(flags);
 	}
 
-	smp_mb();
+	smp_llsc_mb();
 
 	return res != 0;
 }