MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler

This way it doesn't have to use CONFIG_CPU_HAS_LLSC anymore.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/system.h b/arch/mips/include/asm/system.h
index a2e9239..23f68b4 100644
--- a/arch/mips/include/asm/system.h
+++ b/arch/mips/include/asm/system.h
@@ -32,6 +32,9 @@
 
 struct task_struct;
 
+extern unsigned int ll_bit;
+extern struct task_struct *ll_task;
+
 #ifdef CONFIG_MIPS_MT_FPAFF
 
 /*