Pull in a slightly more recent version of libmetal with changes
to the build system to improve integration with Zephyr. This change
will break anything that builds with Zephyr and libmetal (which at this
point is only the open-amp example). Will fix that shortly.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
libmetal itself isn't an ipc library, its a generic HAL abstraction
library so move it into ext/hal where it belongs.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>