[][OpenWrt Dev][Fix register usage in mtk-snand driver]

[Description]
Fix the use of ADDRCNT & BYTELEN.

[Release-log]
N/A

Change-Id: I0b871f226e7b52b0e20a3850385f85e679827fb3
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/4578214
1 file changed