mediatek: fix ubi size for zbtlink zbt z8102ax v2

mediatek: fix ubi size for zbtlink zbt z8102ax v2

According to the factory uboot and firmware[1], the ubi size is set
to 512 MiB (0x20000000) and it exceeds the size of the flash, after
that the uboot and kernel resizes it to 114.5 MiB (0x7280000) instead
of 114.125 MiB (0x7220000). The mismatch of the ubi size causes
kernel fails to read ubi volumes and throws panic.

Trim whitespaces while at it.

1. https://github.com/immortalwrt/immortalwrt/issues/2123#issuecomment-3523744128

Fixes: c908fc7d9591 ("mediatek: add support for Zbtlink ZBT-Z8102AX v2")
Signed-off-by: Tianling Shen <cnsztl@immortalwrt.org>
Link: https://github.com/openwrt/openwrt/pull/20769
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>