nds32: Clean up the coding style

1. Adjust indentation.
2. Unify argument name of each macro.
3. Add space after comma in parameters list.
4. Add space after 'if' keyword.
5. Replace space by tab.
6. Change asm volatile to __asm__ __volatile__

Signed-off-by: Zong Li <zong@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>