doc: unicode trademark and regsiter trademark

Improve this doc to use register trademark and trademark unicode
symbols.

Further, the make rules can benefit from also being passed the argument
ARCH=arc. I see that some zephyr tests use ARCH to select a prj.conf file.

Change-Id: I0650e5d5aba10aa984ebd0be21d0b381dd96dd56
Signed-off-by: Chuck Jordan <cjordan@synopsys.com>