README: update
README: update

The image-prelink feature has been disabled by default in oe-core commit
f9719cc1c3fe9d380336e7af418daf27473b2e8b. We don't need to remove it
explicitly in local.conf.

Signed-off-by: Yi Zhao <408a8b4035f86a985fba8f7a938866debfa07f2b@windriver.com>

jiazhang0/meta-secure-core,jiazhang0/meta-secure-core,jiazhang0/meta-secure-core,jiazhang0/meta-secure-core