drivers: espi: host_subs: npcx: fix LDN register definition of PMCH

The register offset definition of the I/O port Data Base Address
register (0x60, 0x61) and Command/Status Base Address register
(0x62, 0x63) are reversed. This commit fixes it to avoid confusion.

Signed-off-by: Jun Lin <CHLin56@nuvoton.com>
(cherry picked from commit 51cfbd8c)