Copy over the read parts of the ASoC debugfs implementation into regmap,
allowing users to see what the register values the device has are at
runtime. The implementation, especially the support for seeking, is
mostly due to Dimitris Papastamos' work in ASoC.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Allowing the implementation to be multi-file.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>