arm64: dts: ti: k3-j721e: Fix mux-reg-masks in hbmc_mux

arm64: dts: ti: k3-j721e: Fix mux-reg-masks in hbmc_mux

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

While here, update the reg region to include 4 bytes as this
is a 32bit register.

Fixes: 2765149273f4 ("mux: mmio: use reg property when parent device is not a syscon")
Suggested-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20240215141957.13775-1-afd@ti.com
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>