mailbox: imx: support i.MX95 Generic/ELE/V2X MU

Add i.MX95 Generic/ELE/V2X MU support, its register layout is same as
i.MX8ULP, but the Parameter registers would show different
TR/RR. Since the driver already supports get TR/RR from Parameter
registers, not hardcoding the number, this patch just add
the compatible entry to reuse i.MX8ULP S4 cfg data.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>