evtest: Stop using Cgit based archive

The Cgit based archive may change depending on the order of images,
timestamp and like causing checksum to change.

This patch uses the same 1.25 version but fetching it using Git, so no
code changes are done.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Acked-by: Otavio Salvador <otavio@ossystems.com.br>
Acked-by: Cliff Brake <cbrake@bec-systems.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>