Enable power management. This patch enables the clocks before transfer
and disables after the transfer. It also adds the clock description.
Signed-off-by: NShubhrajyoti Datta <shubhraj@xilinx.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>