imx: misc: ele_mu: Update MU TR registers count

According to SRM, the Sentinel MU has 8 TR and 4 RR registers. All
of them are used for ELE message. So update TR count to 8 and fix a
typo in receive msg

Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
1 file changed