ARM: dts: e60k02: fix power button

The power button was only producing irqs, but no key events,
Forced power down with long key press works, so probably
only a short spike arrives at the SoC.
Further investigation shows that LDORTC2 is off after boot
of the vendor kernel. LDORTC2 is shared with a GPIO at the pmic
which probably transfers the button press to the SoC.
That regulator off at boot, so "regulator-boot-on" is definitively
wrong. So remove that.

Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Fixes: c100ea86 ("ARM: dts: add Netronix E60K02 board common file")
Signed-off-by: Shawn Guo <shawnguo@kernel.org>