i3c: master: svc: Fix missing STOP for master request

The controller driver nacked the master request but didn't emit a
STOP to end the transaction. The driver shall refuse the unsupported
requests and return the controller state to IDLE by emitting a STOP.

Signed-off-by: Stanley Chu <yschu@nuvoton.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250318053606.3087121-4-yschu@nuvoton.com


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