azure: gitlab: travis: Update OpenSBI used for RISC-V testing

Change to use OpenSBI release v0.8 generic platform images for QEMU
RISC-V CI testing for azure, gitlab and travis-ci.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
Reviewed-by: Tom Rini <trini@konsulko.com>