Fix MP_SCARA compile (#21686)

Marlin/src/inc/Conditionals_LCD.h

@@ -921,7 +921,7 @@
   #define NORMAL_AXIS Z_AXIS
 #endif
 
-#if EITHER(MORGAN_SCARA, AXEL_TPARA)
+#if ANY(MORGAN_SCARA, MP_SCARA, AXEL_TPARA)
   #define IS_SCARA 1
   #define IS_KINEMATIC 1
 #elif ENABLED(DELTA)

Marlin/src/inc/SanityCheck.h

@@ -1251,7 +1251,7 @@ static_assert(Y_MAX_LENGTH >= Y_BED_SIZE, "Movement bounds (Y_MIN_POS, Y_MAX_POS
 /**
  * Allow only one kinematic type to be defined
  */
-#if MANY(DELTA, MORGAN_SCARA, AXEL_TPARA, COREXY, COREXZ, COREYZ, COREYX, COREZX, COREZY, MARKFORGED_XY)
+#if MANY(DELTA, MORGAN_SCARA, MP_SCARA, AXEL_TPARA, COREXY, COREXZ, COREYZ, COREYX, COREZX, COREZY, MARKFORGED_XY)
   #error "Please enable only one of DELTA, MORGAN_SCARA, AXEL_TPARA, COREXY, COREYX, COREXZ, COREZX, COREYZ, COREZY, or MARKFORGED_XY."
 #endif