dt-bindings: soc: spacemit: Add K3 reset support and IDs

dt-bindings: soc: spacemit: Add K3 reset support and IDs

Update the spacemit,k1-syscon.yaml binding to document K3 SoC reset
support.

K3 reset devices are registered at runtime as auxiliary devices by the
K3 CCU driver. Since K3 reuses the K1 syscon binding, there is no separate
YAML binding file for K3 resets.

Update #reset-cells description to document where reset IDs are defined.

Acked-by: Alex Elder <elder@riscstar.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Guodong Xu <guodong@riscstar.com>
Reviewed-by: Yixun Lan <dlan@kernel.org>
Link: https://lore.kernel.org/spacemit/20260114092742-GYC7933267@gentoo.org/
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>