gpgsm: Fix colon outout of ECC encryption certificates

* sm/keylist.c (print_capabilities): Add arg algo and use it to check
for ECC capabilities.
(list_cert_colon): Call with algo.

This will mark certificates with only keyAgreement usage correctly in
the --with-colons listing.

(cherry picked from commit f5c3f13609361dfeb03722161b1fc93f5a33dcae)