You're on the right track! Here's my take:

Original

Lo there do I see my father.
Lo there do I see my mother and my brothers and my sisters.
Lo they do call to me, bid me to take my place among them in the halls of Valhalla, where the brave may live forever.

Dragon

Ond til zu'u koraav bormahi
Ond til zu'u koraav monahi, zeymahi, ahrk brinahi
Ond til nust komeyt bel ahrk laan zu'u aav niin ko hofkah se Valhalla, kolos fin krilot aal lahney mahfaeraak

Literal Translation:

Lo there I see my father
Lo there I see my mother, my brothers, and my sisters
Lot there they issue (their) summons and request I join them in the halls (house) of Valhalla, in which the brave may live forever

I adapted the last line to be more direct. You could say Valhallasewuth if you'd like, which would mean 'Valhalla of Old,' but that applies better to Atmora since Atmora is a lost, ancient continent in the context of the Greybeard's speech.

This can be simplified a little further, which both helps the rhythm and results in more authentic sentence patterns:

Ond til zu'u koraav dii bormah.
Ond til zu'u koraav dii monah ahrk zeymah ahrk briinah.
Ond nust tinvaak zu'u, aak zu'u aava niin ko hofkah do Valhallasewuth, kolos faal kril lahney unslaad.

Lo there I see my father.
Lo there I see my mother and brothers and sisters.
Lo they speak to me, guide me to join them in the halls of Valhalla of old, where the brave live unendingly.

Note the formal article faal signifying respect to the brave.

Edit: This answer was posted unknowingly of and without reference to paarthurnax's.

wow, thanks I really appriciate it!