regulator: anatop: Set default voltage selector for vddpu

commit fe08be3e upstream.

The code reads the default voltage selector from its register. If the
bootloader disables the regulator, the default voltage selector will be
0 which results in faulty behaviour of this regulator driver.

This patch sets a default voltage selector for vddpu if it is not set in
the register.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>