pinctrl: meson: sync some modify from A4

Set the drive strength before enabling the output to avoid enabling
the output with an unintended drive strength.

Also return the actual output enable state from
PIN_CONFIG_OUTPUT_ENABLE instead of always reporting it as enabled.

Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>