efl/libecore: fix build with gcrypt

When building with gnutls, libecore also needs libgcrypt.

Fixes:

  http://autobuild.buildroot.org/results/4da454d6414cf8f4e638defae9b793fb46a0a072/build-end.log



While we're at it, also explicit the --enable-openssl /
--disable-openssl depending on whether openssl is available or not.

[Peter: only enable gnutls support when both gnutls and gcrypt are enabled]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>