No need to use ip/ and no need to use *_top.vhd.

libraries/technology/ip_arria10/mac_10g/README.txt

libraries/technology/ip_arria10/mac_10g/compile_ip.tcl

libraries/technology/ip_arria10/mac_10g/generate_ip.sh

libraries/technology/ip_arria10/mac_10g/hdllib.cfg

libraries/technology/ip_arria10/mac_10g/ip/hdllib.cfg

...ies/technology/ip_arria10/mac_10g/ip_arria10_mac_10g.qsys

.../technology/ip_arria10/mac_10g/ip_arria10_mac_10g_top.vhd