tplink-safeloader: add EAP225 v1 support

tplink-safeloader: add EAP225 v1 support

Allow creating images compatible with TP-Link's EAP225v1 access point.

The original partition layout is as follows:
    partition fs-uboot base 0x00000 size 0x20000
    partition partition-table base 0x20000 size 0x02000
    partition default-mac base 0x30000 size 0x01000
    partition support-list base 0x31000 size 0x00100
    partition product-info base 0x31100 size 0x00400
    partition soft-version base 0x32000 size 0x00100
    partition os-image base 0x40000 size 0x180000
    partition file-system base 0x1c0000 size 0xc00000
    partition user-config base 0xdc0000 size 0x30000
    partition radio base 0xff0000 size 0x10000

For OpenWrt, the os-image and file-system partition are merged into one
firmware partition, to enable dynamic rootfs partition splits.

Signed-off-by: Sander Vanheule <sander@svanheule.net>