riscv: dts: spacemit: enable PCIe ports on Milk-V Jupiter

riscv: dts: spacemit: enable PCIe ports on Milk-V Jupiter

Enable the two PCIe controller along with and their associated PHY. They
are routed to the M.2 M-key connector and to the PCIe x8 slot.

Add an always-on regulator sourcing 3.3V from the DC-IN input, to power
the PCIe ports.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Yixun Lan <dlan@kernel.org>
Link: https://lore.kernel.org/r/20260326183745.1370642-7-aurelien@aurel32.net
Signed-off-by: Yixun Lan <dlan@kernel.org>