stm32-l5: corrected alt function and other review comments

src/machine/machine_stm32_uart.go

@@ -16,7 +16,7 @@ type UART struct {
 	Buffer          *RingBuffer
 	Bus             *stm32.USART_Type
 	Interrupt       interrupt.Interrupt
-	AltFuncSelector stm32.AltFunc
+	AltFuncSelector uint8
 
 	// Registers specific to the chip
 	rxReg       *volatile.Register32

src/machine/machine_stm32l5.go

@@ -219,7 +219,6 @@ func enableAltFuncClock(bus unsafe.Pointer) {
 		stm32.RCC.APB1ENR1.SetBits(stm32.RCC_APB1ENR1_TIM3EN)
 	case unsafe.Pointer(stm32.TIM2): // TIM2 clock enable
 		stm32.RCC.APB1ENR1.SetBits(stm32.RCC_APB1ENR1_TIM2EN)
-
 	case unsafe.Pointer(stm32.UCPD1): // UCPD1 clock enable
 		stm32.RCC.APB1ENR2.SetBits(stm32.RCC_APB1ENR2_UCPD1EN)
 	case unsafe.Pointer(stm32.FDCAN1): // FDCAN1 clock enable
@@ -232,7 +231,6 @@ func enableAltFuncClock(bus unsafe.Pointer) {
 		stm32.RCC.APB1ENR2.SetBits(stm32.RCC_APB1ENR2_I2C4EN)
 	case unsafe.Pointer(stm32.LPUART1): // LPUART1 clock enable
 		stm32.RCC.APB1ENR2.SetBits(stm32.RCC_APB1ENR2_LPUART1EN)
-
 	case unsafe.Pointer(stm32.TIM17): // TIM17 clock enable
 		stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_TIM17EN)
 	case unsafe.Pointer(stm32.TIM16): // TIM16 clock enable

targets/cortex-m33.json

@@ -1,7 +1,7 @@
 {
-	"inherits": ["cortex-m"],
+    "inherits": ["cortex-m"],
     "llvm-target": "armv7m-none-eabi",
-	"cflags": [
+    "cflags": [
         "--target=armv7m-none-eabi",
         "-mfloat-abi=soft",
         "-Qunused-arguments"