stm32/boards/NUCLEO_L476RG: Add support for RNG, DAC and CAN1.

PLLQ is changed to get CAN working, and I2C1 pins are changed to those
prescribed by the board.

ports/stm32/boards/NUCLEO_L476RG/mpconfigboard.h

@@ -3,15 +3,17 @@
 
 #define MICROPY_HW_HAS_SWITCH       (1)
 #define MICROPY_HW_HAS_FLASH        (1)
+#define MICROPY_HW_ENABLE_RNG       (1)
 #define MICROPY_HW_ENABLE_RTC       (1)
 #define MICROPY_HW_ENABLE_USB       (1)
+#define MICROPY_HW_ENABLE_DAC       (1)
 
 // MSI is used and is 4MHz
 #define MICROPY_HW_CLK_PLLM (1)
 #define MICROPY_HW_CLK_PLLN (40)
-#define MICROPY_HW_CLK_PLLR (2)
-#define MICROPY_HW_CLK_PLLP (7)
-#define MICROPY_HW_CLK_PLLQ (4)
+#define MICROPY_HW_CLK_PLLP (RCC_PLLP_DIV7)
+#define MICROPY_HW_CLK_PLLQ (RCC_PLLQ_DIV2)
+#define MICROPY_HW_CLK_PLLR (RCC_PLLR_DIV2)
 
 // UART config
 #define MICROPY_HW_UART2_TX     (pin_A2)
@@ -23,8 +25,8 @@
 #define MICROPY_HW_FLASH_LATENCY    FLASH_LATENCY_4
 
 // I2C busses
-#define MICROPY_HW_I2C1_SCL (pin_B6)
-#define MICROPY_HW_I2C1_SDA (pin_B7)
+#define MICROPY_HW_I2C1_SCL (pin_B8)
+#define MICROPY_HW_I2C1_SDA (pin_B9)
 #define MICROPY_HW_I2C2_SCL (pin_B10)
 #define MICROPY_HW_I2C2_SDA (pin_B11)
 #define MICROPY_HW_I2C3_SCL (pin_C0)
@@ -40,6 +42,10 @@
 #define MICROPY_HW_SPI2_MISO    (pin_B14)
 #define MICROPY_HW_SPI2_MOSI    (pin_B15)
 
+// CAN bus
+#define MICROPY_HW_CAN1_TX (pin_A12)
+#define MICROPY_HW_CAN1_RX (pin_A11)
+
 // USRSW is pulled low. Pressing the button makes the input go high.
 #define MICROPY_HW_USRSW_PIN        (pin_C13)
 #define MICROPY_HW_USRSW_PULL       (GPIO_NOPULL)
@@ -47,7 +53,7 @@
 #define MICROPY_HW_USRSW_PRESSED    (0)
 
 // LEDs
-#define MICROPY_HW_LED1             (pin_A5) // Green LD2 LED on Nucleo
+#define MICROPY_HW_LED1             (pin_A5) // Green LED on Nucleo
 #define MICROPY_HW_LED_ON(pin)      (mp_hal_pin_high(pin))
 #define MICROPY_HW_LED_OFF(pin)     (mp_hal_pin_low(pin))