libical introduce pthread support after 0.47, but lead deadlock with missing
some unlock code. This makes dates start hang.
Add new patch to properly release mutex.
[YOCTO #1825] got fixed.
(From OE-Core rev: 584abc5f3d6cbaf8f8bf09123e8abc421f0699a8)
Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>