Cmake : Don't try to build tarballs on OSX if OSX_PACKAGE is set
Cmake : Don't try to build tarballs on OSX if OSX_PACKAGE is set

Otherwise they turn out empty.

Paul:
- Make sure ENABLE_PACKAGING is only available if OSX_PACKAGE is not
set.

Signed-off-by: Robin Getz <c66e5a86ef9317cf35cecb2ed063996b2100ed4b@analog.com>
Signed-off-by: Paul Cercueil <73d292422978d45c9eeef455bb1b24a0db453722@analog.com>

analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio,analogdevicesinc/libiio