arch: use ASM_NL instead of ';' for assembler new line character in the macro

For some assemblers, they use another character as newline in a macro
(e.g. arc uses '`'), so for generic assembly code, need use ASM_NL (a
macro) instead of ';' for it.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>