package/libcap: bump version to 2.45

This libcap release is now able to build on environments w/o thread support.

- add PTHREADS make arg to allow building without thread support
- add SHARED make arg (replace of DYNAMIC)
- remove patch that function is now in upstream (SHARED)

Fixes:
http://autobuild.buildroot.net/results/fc1e7573327c7412dfa45b45a96966d993c7fc86/



Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
CC: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Heiko Thiery <heiko.thiery@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>