MAINTAINERS: fsl-mc: Add second maintainer

Add Stuart Yoder as additional maintainer of fsl-mc bus driver.

Signed-off-by: Stuart Yoder <stuart.yoder@nxp.com>
Acked-by: German Rivera <german.rivera@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>