ASoC: sigmadsp: Refuse to load firmware files with a non-supported version

commit 50c0f21b42dd4cd02b51f82274f66912d9a7fa32 upstream.

Make sure to check the version field of the firmware header to make sure to
not accidentally try to parse a firmware file with a different layout.
Trying to do so can result in loading invalid firmware code to the device.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>