ti_config_fragments: v8_rpmsg: Enable K3 DSP remoteproc support

Add support to build the K3 DSP remoteproc driver to enable both the
C66x and the single C71x DSP processor subsystems present within the
MAIN domain on J721E SoCs. The other required remoteproc core, OMAP
Mailbox, virtio/rpmsg modules were already enabled. These are the
minimum required modules for enabling remoteproc and rpmsg communication
with the C66x and C71x remote processors on the J721E family of SoCs.

Signed-off-by: Suman Anna <s-anna@ti.com>