[Spec] First draft for SNPE-devel dummy package

[Spec] First draft for SNPE-devel dummy package

The Snapdragon Neural Processing Engine (SNPE) is a Qualcomm Snapdragon
software accelerated runtime for the execution of deep neural networks.
Because of the license issue, the header and binary files of SNPE cannot
be opened in public.

To support the NNStreamer filter for SNPE on both In-House build infra
and those of the public, this repo generates a snpe-devel.rpm package,
which contains the snpe-dummy.pc file. In the case of the dummy SNPE
package, nnstreamer-snpe rpm is created but contains no files.

Signed-off-by: Sangjung Woo <sangjung.woo@samsung.com>