arm: sunxi: Reduce inrush current on Olimex A20-OLinuXino_MICRO configs

This change fix reboot, both configurations
were tested on my Olimex A20 Micro Rev E with debian-12.

This issue was also present and fixed on A20 Lime2 (in 8311e84b),
quoting Olliver Schinagl:

    The lime2 features a too large capacitor on the LDO3 output, which
    causes the PMIC to shutdown when enabling power. To be able to still
    boot up however, we must gradually enable power on LDO3 for this board.
    We do this by enabling both the inrush quirk and the maximum slope the
    AXP209 supports.

Link: https://bugs.debian.org/1060752


Cc: Olliver Schinagl <oliver@schinagl.nl>
Cc: Priit Laes <plaes@plaes.org>
Cc: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Philippe Coval <rzr@users.sf.net>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>