rockchip: rk3399: move sysreset-gpio logic to TPL

rockchip: rk3399: move sysreset-gpio logic to TPL

If TPL_GPIO and TPL_PINCTRL_ROCKCHIP are enabled and a sysreset-gpio is
provided in the TPL Device Tree, this will trigger a system reset
similar to what's currently been done in SPL whenever the RK3399 "warm"
boots. Because there's currently only one user of sysreset-gpio logic,
and TPL is enabled on that board, so let's migrate the logic and that
board to do it in TPL.

There are three reasons for moving this earlier:
- faster boot time as we don't need to reach SPL to be able to reset the
  system on a condition we know is already met in TPL,
- have less code to be impacted by the issue this system reset works
  around (that is, "unclean" SoC registers after a reboot),
- less confusion around the reason for restarting. Indeed when done from
  SPL, the following log can be observed:

"""
U-Boot TPL 2025.01-rc1-00165-gd79216ca9878-dirty (Nov 05 2024 - 15:31:45)
Channel 0: DDR3, 666MHz
BW=32 Col=10 Bk=8 CS0 Row=16 CS=1 Die BW=16 Size=2048MB
Channel 1: DDR3, 666MHz
BW=32 Col=10 Bk=8 CS0 Row=16 CS=1 Die BW=16 Size=2048MB
256B stride
Trying to boot from BOOTROM
Returning to boot ROM...

U-Boot SPL 2025.01-rc1-00165-gd79216ca9878-dirty (Nov 05 2024 - 15:31:45 +0100)
Trying to boot from MMC2

U-Boot TPL 2025.01-rc1-00165-gd79216ca9878-dirty (Nov 05 2024 - 15:31:45)
"""

possibly hinting at an issue within the SPL when loading the fitImage
from MMC2 instead of the normal course of events (a system reset).

Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>
Reviewed-by: Paul Kocialkowski <paulk@sys-base.io>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>