staging: ccree: break send_request and fix ret val

staging: ccree: break send_request and fix ret val

The send_request() function was handling both synchronous
and asynchronous invocations, but were not handling
the asynchronous case, which may be called in an atomic
context, properly as it was sleeping.

Start to fix the problem by breaking up the two use
cases to separate functions calling a common internal
service function and return error instead of sleeping
for the asynchronous case.

The next patch will complete the fix by implementing
proper backlog handling.

Fixes: b47cbd53c7 ("staging: ccree: introduce CryptoCell HW driver").
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>