config: remove redundant DPAA2 build

config: remove redundant DPAA2 build

dpaa and dpaa2 config have evolved to be same. The same binary
can now work across the platforms. So, there is no need to maintain
two different build configs.
The dpaa config shall work for both generation of dpaa platforms.

Signed-off-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>