am335x-evm.conf: Use soft assignment for MKUBIFS_ARGS, UBINIZE_ARGS
am335x-evm.conf: Use soft assignment for MKUBIFS_ARGS, UBINIZE_ARGS

This is allow user to override them in their configuration

Signed-off-by: Ankur Tyagi <7ecc23b02c72673ec86df31b2563d9025431aaf6@gallagher.com>
Signed-off-by: Denys Dmytriyenko <d29de71aea38aad3a87d486929cb0aad173ae612@ti.com>

rcn-ee/meta-ti,rcn-ee/meta-ti,rcn-ee/meta-ti,rcn-ee/meta-ti