mfd: stmpe: Remove rotator block from probe

Remove rotator block from probe, it is not used in any device tree file,
there is no related cell defined, it's just dead non-working code with no
of_compatible for it.

This is a preliminary change to allow probing by of_compatible and not
by a fixed name.

Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20220712163345.445811-2-francesco.dolcini@toradex.com