colibri_imx6: revert fuse value set in mfgr_fuse

colibri_imx6: revert fuse value set in mfgr_fuse

We have two commands to change the bootmode fuses:
mfgr_fuse which set fuse 0/5 and 0/6
and
updt_fuse which burns bit 4 of 0/5.

Before Image 2.6 we fused in mfgr_fuse 0x5062, which boots
from the user partition of the eMMC.
To workaround certain hangs we moved to fastboot mode and
using the first bootpartition of the eMMC requiring a fuse
value of 0x5072 which could be achived by the then added
updt_fuse command. At the same time the mfgr_fuse command
was changed to also fuse 0x5072, revert that second change
so that one can fuse both values, one with just mfgr_fuse
and the later with mfgr_fuse;updt_fuse.

Note that the mfgr_fuse command is only needed at module
production time, a customer might need to use updt_fuse
when upgrading an older module to be compatible with a
newer image. The command is integrated into the image
update scripts.

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Acked-by: Stefan Agner <stefan.agner@toradex.com>
Acked-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>