mpc85xx: enable XZ_DEC_BCJ and XZ_DEC_POWERPC support

mpc85xx: enable XZ_DEC_BCJ and XZ_DEC_POWERPC support

Squashfs is unable to decompress some blocks without that:

[  199.494500] SQUASHFS error: xz_dec_run error, data probably corrupt
[  199.500910] SQUASHFS error: squashfs_read_data failed to read block 0xbff26
[  199.508016] SQUASHFS error: Unable to read data cache entry [bff26]
[  199.514440] SQUASHFS error: Unable to read page, block bff26, size 153f8
[  199.521311] SQUASHFS error: Unable to read data cache entry [bff26]
[  199.527724] SQUASHFS error: Unable to read page, block bff26, size 153f8
[  199.534594] SQUASHFS error: Unable to read data cache entry [bff26]
[  199.541009] SQUASHFS error: Unable to read page, block bff26, size 153f8

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35590 3c298f89-4303-0410-b956-a3cf2f4a3e73