sgtl5000 has two required supplies: VDDA and VDDIO and one optional supply:
VDDD, so document this properly.

Not passing VDDA and VDDIO prevents the driver to probe successfully.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Since commit 9e13f345 (ASoC: sgtl5000: Let the codec acquire its clock) , the
'clocks' entry is mandatory, so update the binding doc.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

Add description for 'reg' field.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

It moves and renames sgtl5000 device tree binding document to make
it aligned with other codecs.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

It adds device tree probe support for sgtl5000 driver.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NLiam Girdwood <lrg@ti.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>