MAINTAINERS: Remove Conor Culhane from Silvaco I3C

MAINTAINERS: Remove Conor Culhane from Silvaco I3C

Conor Culhane's email address (conor.culhane@silvaco.com) is no longer
accessible, and there has been no activity from him on
https://lore.kernel.org/linux-i3c/ in the past two years.

To avoid email delivery failure messages when sending patches to the I3C
mailing list, remove him from the Maintainers section and move him to the
credits.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20250204161151.2179596-1-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>