drm: drm_fourcc: Add generic alias for 16_16_TILE modifier

 * When adding a new token please document the layout with a code comment,

 * similar to the fourcc codes above. drm_fourcc.h is considered the

 * authoritative source for all of these.

 *

 * Generic modifier names:

 *

 * DRM_FORMAT_MOD_GENERIC_* definitions are used to provide vendor-neutral names

 * for layouts which are common across multiple vendors. To preserve

 * compatibility, in cases where a vendor-specific definition already exists and

 * a generic name for it is desired, the common name is a purely symbolic alias

 * and must use the same numerical value as the original definition.

 *

 * Note that generic names should only be used for modifiers which describe

 * generic layouts (such as pixel re-ordering), which may have

 * independently-developed support across multiple vendors.

 *

 * In future cases where a generic layout is identified before merging with a

 * vendor-specific modifier, a new 'GENERIC' vendor or modifier using vendor

 * 'NONE' could be considered. This should only be for obvious, exceptional

 * cases to avoid polluting the 'GENERIC' namespace with modifiers which only

 * apply to a single vendor.

 *

 * Generic names should not be used for cases where multiple hardware vendors

 * have implementations of the same standardised compression scheme (such as

 * AFBC). In those cases, all implementations should use the same format

 * modifier(s), reflecting the vendor of the standard.

 */

#define DRM_FORMAT_MOD_GENERIC_16_16_TILE DRM_FORMAT_MOD_SAMSUNG_16_16_TILE

/*

 * Invalid Modifier

 *