exynos_omx: multi_thread: Add ThumbnailMode decoding.

exynos_omx: multi_thread: Add ThumbnailMode decoding.

Extension name:
 - EXYNOS_INDEX_PARAM_ENABLE_THUMBNAIL "OMX.SEC.index.enableThumbnailMode"

if you want enable thumbnail decoding,
Use SetParameter and EXYNOS_OMX_VIDEO_THUMBNAILMODE struct.

typedef struct _EXYNOS_OMX_VIDEO_THUMBNAILMODE {
    OMX_U32 nSize;
    OMX_VERSIONTYPE nVersion;
    OMX_U32 nPortIndex;
    OMX_BOOL bEnable;
} EXYNOS_OMX_VIDEO_THUMBNAILMODE;

Change-Id: I199f286bfbd35266b6f319538a55e64a71070f8e
Signed-off-by: SeungBeom Kim <sbcrux.kim@samsung.com>
Bug: 10192533