overlay-hacks kernel module to test overlay feature
- currently tries to overlay overlay-test.dtbo using request_firmware on insmod
- export of overlay functions required

Caution:
- make sure to compile the base dtb with -@ flag to dtc, stock kernel doesn't.
- make sure that nodes being referred to in the base have labels so that phandles are generated.

Signed-off-by: Joel A Fernandes <joelagnel@ti.com>

fixup

Signed-off-by: Joel A Fernandes <joelagnel@ti.com>

OF: export functions required by overlay-hacks module

Signed-off-by: Joel A Fernandes <joelagnel@ti.com>
    dtc: Generate phandles as a CRC of the label or path of a node

    This has the advantage that for DT overlays, dynamic fixup of nodes
    is not required. Also, nothing changes with the DT format so existing
    systems should work.

Signed-off-by: Joel A Fernandes <joelagnel@ti.com>
dtc: Generate phandle as hash of reference

For non-existent nodes if -@ is passed, generate hash of the reference.

Signed-off-by: Joel A Fernandes <joelagnel@ti.com>