This is most definitely an adaptation of The Brothers Lionheart by Astrid Lindgren, who is better known for Pippi Longstocking. The original Swedish title is Bröderna Lejonhjärta (1973).
A Swedish movie adaptation was made in 1977, which is probably what you've seen.
(...) a magical land called something like "yanki-hola".
The land in question is called "Nangijala".
Karl, a 10 year old boy, is bedridden and expected to die soon. His older brother Jonatan tells him stories about Nangijala, where all people go when they die. When a fire breaks out in heir home, Jonatan saves his younger brother by taking him on his back and jumping out of the window, giving his life for his younger brother and reaching Nangijala before Karl. When Karl dies some time later, he meets his brother in Nangijala.
But Nangijala isn't a happy afterlife. The valley where Jonatan and Karl end up, the Cherry Valley, is indeed a happy place, but the adjacent Thorn Rose Valley is controlled by the tyrant Tengil and a dragon named Katla, who is under Tengil's control by way of a special trumpet.
The two brothers play a crucial role in freeing the Thorn Rose Valley from Tengil's rule.
In the end, the story repeats itself, reversed, with Karl taking a wounded Jonatan on his back, jumping to their deaths in that world and onto the next world, Nangilima.
