reset: spacemit: Extract common K1 reset code

reset: spacemit: Extract common K1 reset code

Extract the common reset controller code from the K1 driver into
separate reset-spacemit-common.{c,h} files to prepare for additional
SpacemiT SoCs that share the same reset controller architecture.

The common code includes handlers for reset assert and deassert
operations and probing for auxiliary bus devices.

Changes during extraction:
- Module ownership: Use dev->driver->owner instead of THIS_MODULE in
  spacemit_reset_controller_register() to correctly reference the
  calling driver's module.
- Rename spacemit_reset_ids to spacemit_k1_reset_ids.
- Define new namespace "RESET_SPACEMIT" for the exported common
  functions (spacemit_reset_probe) and update K1 driver to import it.

This prepares for additional SpacemiT SoCs (K3) that share the same reset
controller architecture.

Reviewed-by: Alex Elder <elder@riscstar.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>