linux-phytec-ti

dmaengine: at_hdmac: fix race while monitoring channel status

We were reading channel status then taking a lock. This lead to a race because
this lock may delay us and then make this channel not idle anymore.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>