target/arm: use the common interface for WRITE0/WRITEC in arm-semi

Now we have a common semihosting console interface use that for our
string output. However ARM is currently unique in also supporting
semihosting for linux-user so we need to replicate the API in
linux-user. If other architectures gain this support we can move the
file later.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
3 files changed