Change offset in mux-reg-masks property for serdes_ln_ctrl node
since reg-mux property is used in compatible.

Fixes: 27651492 ("mux: mmio: use reg property when parent device is not a syscon")
Signed-off-by: Chintan Vankar <c-vankar@ti.com>
Acked-by: Andrew Davis <afd@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Link: https://lore.kernel.org/r/20240213080348.248916-1-s-vadapalli@ti.comSigned-off-by: Vignesh Raghavendra <vigneshr@ti.com>