Change values to u32, there's no need for them to be 64-bit.
Reported-by: Colin Ian King <colin.king@canonical.com>
Suggested-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This will be required to support Volta, but also allows us to remove code
that's duplicated for each channel type already.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>