bcm63xx: lzma-loader: allow bigger ramdisks

bcm63xx: lzma-loader: allow bigger ramdisks

Some (older) CFEs are loaded at 0x80401000 and ramdisks are loaded at
0x80010000, which means that ramdisk size limit is 0x3F1000 (almost 4M).
Therefore, current ramdisks (~4MB) are overwritting CFE in these devices,
which results in a crash.

This commit changes the address where ramdisks are loaded to 0x80a00000,
which is the same address where kernel is loaded when booting from the flash.
Therefore, lzma-loader will now be loaded at 0x80a00000, but it will still
decompress the kernel at 0x80010000.

Tested with huawei,hg556a-b, which has its CFE loaded at 0x80401000.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>