Documentation: pinctrl: palmas: Add ti,palmas-powerhold-override property definition

commit 0ea66f76ba17a4b229caaadd77de694111b21769 upstream.

GPIO7 is configured in POWERHOLD mode which has higher priority
over DEV_ON bit and keeps the PMIC supplies on even after the DEV_ON
bit is turned off. This property enables driver to over ride the
POWERHOLD value to GPIO7 so as to turn off the PMIC in power off
scenarios.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>