ext: simplelink: Update user.h

We are using the external spawn option, hence must make a change
to point to our os_Spawn implementation.

We are also supplying errno values that are missing from Zephyr errno.h
and the external errno setter function, to allow the SimpleLink
driver.c to compile.

Signed-off-by: Vincent Wan <vincent.wan@linaro.org>
1 file changed