opencv: fix compile issues
The first patch from Debian fixes following autobuild failure:
http://autobuild.buildroot.net/results/
eda5c6c43da40a342e0f545a348d2f865eb5ccf2/
Tested with ARM build without a regression.
The second patch fixes musl arm autobuild failure:
http://autobuild.buildroot.net/results/
6a397de789c809984b851a304078e26b2ac58974/
Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
Tested-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>