pinctrl: mvebu: armada-39x: normalize SATA present functionality naming

This commit makes the naming of SATA related MPP functions consistent
accross SoCs by adjusting the Armada 39x definition to use "prsnt"
instead of "present".

Since only the subnames are changed, the DT binding is not modified at
all.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>