i3c: dw: Add shutdown support to dw_i3c_master driver

Add shutdown handler to the Synopsys DesignWare I3C master driver,
ensuring the device is gracefully disabled during system shutdown.

The shutdown handler cancels any pending hot-join work and disables
interrupts.

Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
Link: https://lore.kernel.org/r/20250730151207.4113708-1-manikanta.guntupalli@amd.com


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>