external/opal-prd: Drop final use of ffs_open_image()
external/opal-prd: Drop final use of ffs_open_image()

ffs_open_image() is only called from one place and its function has been
superseded by the blocklevel_device interface to access files/mtd/flash.

Ultimately it looks like opal-prd should be converted to use the full set
of features provided by blocklevel but for now this patch allows code to be
ripped out of libffs.

Signed-off-by: Cyril Bur <6ce38dade8c4b52fd55c193fae70fd1d1275c3c3@au1.ibm.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

shenki/skiboot,qemu/skiboot,open-power/skiboot,legoater/skiboot,qemu/skiboot,open-power/skiboot,open-power/skiboot,open-power/skiboot,stewart-ibm/skiboot,stewart-ibm/skiboot,legoater/skiboot,shenki/skiboot,mikey/skiboot,shenki/skiboot,legoater/skiboot,shenki/skiboot,open-power/skiboot,qemu/skiboot,shenki/skiboot,mikey/skiboot,qemu/skiboot,legoater/skiboot,mikey/skiboot,qemu/skiboot,legoater/skiboot,stewart-ibm/skiboot