Move emul.h out of the top level include/ dir into
include/drivers/emul.h and deprecated the old location.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Add an emulation controller which routes SPI traffic to an attached
emulator. Only one emulator is supported per bus at present, since
chip-selction functionality is not present.
This allows drivers for SPI peripherals to be tested on systems that
don't have that peripheral attached, with the emulator handling the SPI
traffic.
Signed-off-by: Simon Glass <sjg@chromium.org>