test: check pkparse with compressed ec

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/tests/data_files/ec_256_pub.comp.pem b/tests/data_files/ec_256_pub.comp.pem
new file mode 100644
index 0000000..bf9655d
--- /dev/null
+++ b/tests/data_files/ec_256_pub.comp.pem
@@ -0,0 +1,4 @@
+-----BEGIN PUBLIC KEY-----
+MDkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDIgADd3Jlb4FLOZJ51eHxeB+sbwmaPFyh
+sONTUYNLCLZeC1c=
+-----END PUBLIC KEY-----