media: venus: assign unique bus_info strings for encoder and decoder

media: venus: assign unique bus_info strings for encoder and decoder

The Venus encoder and decoder video devices currently report the same
bus_info string ("platform:qcom-venus").

Assign unique bus_info identifiers by appending ":dec" and ":enc" to the
parent device name. With this change v4l2-ctl will display two separate
logical devices

Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez@oss.qualcomm.com>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Bryan O'Donoghue <bod@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>