sysota: install machine-specific sysotad.conf

The systoa package now provides standard sysotad.conf configuration
file, which is safe to install on all systems. For the MACHINE
"raspberrypi4-64" a special sysotad.conf is provided, one that
enables the pi-boot specific boot loader logic.

The entire sysota package becomes MACHINE-specific to avoid populating
the cache with the wrong config settings across builds.

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@huawei.com>