motu: report the optical control register read from the device when obtaining the optical port modes.  For debug purposes only.

git-svn-id: http://subversion.ffado.org/ffado/trunk/libffado@2420 2be59082-3212-0410-8809-b0798e1608f0
rme: unlike some other interfaces, SPDIF is available on these interfaces at 4x rates (noticed by Ilia on the mailing list).  The bandwidth calculation in prepare() was correct, by luck.

git-svn-id: http://subversion.ffado.org/ffado/trunk/libffado@2421 2be59082-3212-0410-8809-b0798e1608f0
motu: correct the detection of the optical port mode for mark3 devices.  Previously the identification of toslink and adat modes were switched.

git-svn-id: http://subversion.ffado.org/ffado/trunk/libffado@2422 2be59082-3212-0410-8809-b0798e1608f0