ARC: handle the difference of assembly macro definition

GNU toolchain and MWDT (Metware) toolchain have different style
for accessing arguments in assembly macro. Implement the
preprocessor macro to handle the difference.

Make all ASM macros in swap_macros.h compatible for both ARC
toolchains.

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>