drm: apple: Support up to 3 DCP instances.

Signed-off-by: Janne Grunau <j@jannau.net>

Author: jannau

drivers/gpu/drm/apple/apple_drv.c

@@ -46,7 +46,7 @@
 
 #define FRAC_16_16(mult, div)    (((mult) << 16) / (div))
 
-#define MAX_COPROCESSORS 2
+#define MAX_COPROCESSORS 3
 
 struct apple_drm_private {
 	struct drm_device drm;