dra7xx-evm.conf: add back dra71-evm-nand.dtb and dra76-evm-tfp410.dtb
dra7xx-evm.conf: add back dra71-evm-nand.dtb and dra76-evm-tfp410.dtb

Signed-off-by: Denys Dmytriyenko <d29de71aea38aad3a87d486929cb0aad173ae612@ti.com>

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