buildroot

sunxi-tools: bump version, add hash

Upstream has reworked its build system, so it now supports PREFIX and 'make
install', so use those.

Notice that the tools have also gained a sunxi- prefix, so use that as well
when installing the target variant.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>