osx: use MP_KEY_* instead of MK_* for media keys

In 213ad5d6c I added `MK_*` key bindings overlooking the fact that mpv already
has `MP_KEY_*` for media keys.

etc/input.conf

@@ -171,11 +171,6 @@
 #AR_VDOWN add volume -1
 #AR_VDOWN_HOLD add chapter -1
 
-# Media Keys section
-#MK_PLAY cycle pause
-#MK_PREV playlist_prev
-#MK_NEXT playlist_next
-
 # Joystick section
 # WARNING: joystick support has to be explicitly enabled at
 #          compiletime with --enable-joystick

mpvcore/input/input.c

@@ -429,10 +429,6 @@ static const struct key_name key_names[] = {
   { MP_AR_VDOWN,        "AR_VDOWN" },
   { MP_AR_VDOWN_HOLD,   "AR_VDOWN_HOLD" },
 
-  { MP_MK_PLAY,         "MK_PLAY" },
-  { MP_MK_PREV,         "MK_PREV" },
-  { MP_MK_NEXT,         "MK_NEXT" },
-
   { MP_AXIS_UP,         "AXIS_UP" },
   { MP_AXIS_DOWN,       "AXIS_DOWN" },
   { MP_AXIS_LEFT,       "AXIS_LEFT" },

mpvcore/input/keycodes.h

@@ -201,12 +201,6 @@
 #define MP_AR_VDOWN       (MP_AR_BASE + 12)
 #define MP_AR_VDOWN_HOLD  (MP_AR_BASE + 13)
 
-// Apple Media Keys input module
-#define MP_MK_BASE        (MP_KEY_BASE+0xF0)
-#define MP_MK_PLAY        (MP_MK_BASE + 0)
-#define MP_MK_PREV        (MP_MK_BASE + 1)
-#define MP_MK_NEXT        (MP_MK_BASE + 2)
-
 // Mouse wheels or touchpad input
 #define MP_AXIS_BASE      (MP_KEY_BASE+0x100)
 #define MP_AXIS_UP        (MP_AXIS_BASE+0)

osdep/macosx_events.m

@@ -242,9 +242,9 @@ void cocoa_put_key_with_modifiers(int keycode, int modifiers)
 - (BOOL)handleMediaKey:(NSEvent *)event
 {
     NSDictionary *keymap = @{
-        @(NX_KEYTYPE_PLAY):    @(MP_MK_PLAY),
-        @(NX_KEYTYPE_REWIND):  @(MP_MK_PREV),
-        @(NX_KEYTYPE_FAST):    @(MP_MK_NEXT),
+        @(NX_KEYTYPE_PLAY):    @(MP_KEY_PLAY),
+        @(NX_KEYTYPE_REWIND):  @(MP_KEY_PREV),
+        @(NX_KEYTYPE_FAST):    @(MP_KEY_NEXT),
     };
 
     return [self handleKey:mk_code(event)