dt: Update device tree document for AR6003

Update device tree document with properties required for AR6003
SDIO device.
Also change regulator properties to not to prefix chip name as
regulator preperty only reflects regulator to be used.

Change-Id: I16b1539551268c6d0c48f3fed2a06154b6c17990
Signed-off-by: Prashanth Bhatta <bhattap@codeaurora.org>