i3c: master: svc: Fix npcm845 invalid slvstart event

I3C HW may generate an invalid SlvStart event when emitting a STOP.
If it is a true SlvStart, the MSTATUS state is SLVREQ. Check the
MSTATUS state to ignore the false event.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Stanley Chu <yschu@nuvoton.com>
Link: https://lore.kernel.org/r/20250306075429.2265183-5-yschu@nuvoton.com


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