dts: npcx: workaroud bbram 1st byte issue for npcx4

Apply the workaround for the issue "BBRAM First Byte" in the
NPCX49nF_Errata. This bypass limits the access to the BBRAMs' first byte
(i.e., the offset 0). As a result, only 127 bytes are available in npcx4
chips.

Signed-off-by: Jun Lin <CHLin56@nuvoton.com>