staging: ccree: use signal safe completion wait

We were waiting for a completion notification of HW DMA
operation using an interruptible wait which can result
in data corruption if a signal interrupted us while
DMA was not yet completed.

Fix this by moving to uninterrupted wait.

Fixes: abefd674 ("staging: ccree: introduce CryptoCell HW driver").

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>