HAL_ChibiOS: fixed I2C4 DMA streams

There is an error in the datasheet. See
https://community.st.com/thread/50484-documentation-error-on-dma-channels-for-i2c4-on-stm32f7

libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F767xx.py

@@ -64,8 +64,8 @@ DMA_Map = {
 	"I2C2_TX" 	:	[(1,7,7),(1,4,8)],
 	"I2C3_RX" 	:	[(1,2,3),(1,1,1)],
 	"I2C3_TX" 	:	[(1,4,3),(1,0,8)],
-	"I2C4_RX" 	:	[(1,1,8),(1,2,2),(1,5,2)],
-	"I2C4_TX" 	:	[(1,6,8)],
+	"I2C4_RX"    	:	[(1,2,2),(1,1,8)],
+	"I2C4_TX" 	:	[(1,6,8),(1,5,2)],
 	"JPEG_IN" 	:	[(2,0,9),(2,3,9)],
 	"JPEG_OUT" 	:	[(2,1,9),(2,4,9)],
 	"QUADSPI" 	:	[(2,2,11),(2,7,3)],