added a few constants

KFM_CMD_SET_MODE, PRIM_MEDIA_MAX_HEIGHT_PIXELS,
PRIM_MEDIA_MAX_URL_LENGTH, PRIM_MEDIA_MAX_WHITELIST_COUNT,
PRIM_MEDIA_MAX_WHITELIST_SIZE, PRIM_MEDIA_MAX_WIDTH_PIXELS,
PRIM_MEDIA_PARAM_MAX