Add support for Teensy 4.1 specific pins

Mostly the same as T4, except
a few different alternate Uart pins, plus Serial8 was added.

WS2812Serial.cpp

 
 #elif defined(__IMXRT1062__)
 	  case 1: // Serial1
+#if defined(ARDUINO_TEENSY41)
+	  case 53:
+#endif
 		uart = &IMXRT_LPUART6; 
 		CCM_CCGR3 |= CCM_CCGR3_LPUART6(CCM_CCGR_ON);
 		hwtrigger = DMAMUX_SOURCE_LPUART6_TX; 
 		hwtrigger = DMAMUX_SOURCE_LPUART3_TX; 
 		break;
 	  case 20: // Serial5
+#if defined(ARDUINO_TEENSY40)
 	  case 39: // Serial5 alt
+#elif defined(ARDUINO_TEENSY41)
+	  case 47:
+#endif
 		uart = &IMXRT_LPUART8; 
 		CCM_CCGR6 |= CCM_CCGR6_LPUART8(CCM_CCGR_ON);
 		hwtrigger = DMAMUX_SOURCE_LPUART8_TX; 
 		CCM_CCGR5 |= CCM_CCGR5_LPUART7(CCM_CCGR_ON);
 		hwtrigger = DMAMUX_SOURCE_LPUART7_TX; 
 		break;
+#if defined(ARDUINO_TEENSY41)
+	  case 35:
+		uart = &IMXRT_LPUART5; 
+		CCM_CCGR3 |= CCM_CCGR3_LPUART5(CCM_CCGR_ON);
+		hwtrigger = DMAMUX_SOURCE_LPUART5_TX; 
+		break;
+#endif		
 #endif
 	  default:
 		return false; // pin not supported

examples/BasicTest/BasicTest.ino

 //   Teensy 3.5:  1, 5, 8, 10, 26, 32, 33, 48
 //   Teensy 3.6:  1, 5, 8, 10, 26, 32, 33
 //   Teensy 4.0:  1, 8, 14, 17, 20, 24, 29, 39
+//   Teensy 4.1:  1, 8, 14, 17, 20, 24, 29, 35, 47, 53
 
 byte drawingMemory[numled*3];         //  3 bytes per LED
 DMAMEM byte displayMemory[numled*12]; // 12 bytes per LED

examples/BasicTest_RGBW/BasicTest_RGBW.ino

 //   Teensy 3.5:  1, 5, 8, 10, 26, 32, 33, 48
 //   Teensy 3.6:  1, 5, 8, 10, 26, 32, 33
 //   Teensy 4.0:  1, 8, 14, 17, 20, 24, 29, 39
+//   Teensy 4.1:  1, 8, 14, 17, 20, 24, 29, 35, 47, 53
 
 byte drawingMemory[numled*4];         //  4 bytes per LED for RGBW
 DMAMEM byte displayMemory[numled*16]; // 16 bytes per LED for RGBW

examples/FastLED_Cylon/FastLED_Cylon.ino

 //   Teensy 3.5:  1, 5, 8, 10, 26, 32, 33, 48
 //   Teensy 3.6:  1, 5, 8, 10, 26, 32, 33
 //   Teensy 4.0:  1, 8, 14, 17, 20, 24, 29, 39
+//   Teensy 4.1:  1, 8, 14, 17, 20, 24, 29, 35, 47, 53
+
 #define DATA_PIN 1
 
 // Define the array of leds