dts: arm: stm32u5: Fix LSE default driving-capability
dts: arm: stm32u5: Fix LSE default driving-capability

According to errata sheet, LSE driving-capability should not be set
to 0 or 1.
Set it to 2 as default value.

Signed-off-by: Erwan Gouriou <de4d967452b83bb0e37525652734e7d9163b6a4c@linaro.org>

finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr