boards: arm: disco_l475_iot1: Enable MSI PLL mode for USB

The MSI PLL mode has been disabled but can be used since LSE is
populated on disco_l475_iot1 board. This is requested to enable
USB device controller support.

Fixes #18717

Signed-off-by: Loic Poulain <[email protected]>

Author: Loic Poulain

boards/arm/disco_l475_iot1/disco_l475_iot1_defconfig

@@ -36,6 +36,10 @@ CONFIG_CLOCK_STM32_AHB_PRESCALER=1
 CONFIG_CLOCK_STM32_APB1_PRESCALER=1
 CONFIG_CLOCK_STM32_APB2_PRESCALER=1
 
+# LSE oscillator is populated, enable MSI PLL-Mode
+CONFIG_CLOCK_STM32_LSE=y
+CONFIG_CLOCK_STM32_MSI_PLL_MODE=y
+
 # console
 CONFIG_CONSOLE=y
 CONFIG_UART_CONSOLE=y