[PATCH] [ARC] atomics: Add operand to DMB instruction

[Claudiu Zissulescu]

Hi,
> 
> 2019-01-18  Vineet Gupta <vgupta@synopsys.com>
> 
>        * config/arc/atomic.md: Add operand to DMB instruction
> 

This is ok. I'll push it asap,
Claudiu