exa2pro/starpu-max: porting work to Maxeler DFE @ 64c7e51ce4b5bb1a1c0b5e5dffb2b69e564a85d8

Samuel Thibault d7f11524bf Skip test if cholesky_tag is not available (no blas)		13 lat temu
..
dummy_sched.c	0ee3ebd86c examples: return 77 when there are no devices.	13 lat temu
schedulers.sh	d7f11524bf Skip test if cholesky_tag is not available (no blas)	13 lat temu