README update STM32L0 to CUBE V1.12.0

Author: JeanMarcR

targets/TARGET_STM/README.md

@@ -70,7 +70,7 @@ This table summarizes the STM32Cube versions currently used in Mbed OS master br
 | G0          |    1.4.1     | https://github.com/STMicroelectronics/STM32CubeG0 |
 | G4          |    1.1.0     | https://github.com/STMicroelectronics/STM32CubeG4 |
 | H7          |    1.8.0     | https://github.com/STMicroelectronics/STM32CubeH7 |
-| L0          |    1.11.3    | https://github.com/STMicroelectronics/STM32CubeL0 |
+| L0          |    1.12.0    | https://github.com/STMicroelectronics/STM32CubeL0 |
 | L1          |    1.10.2    | https://github.com/STMicroelectronics/STM32CubeL1 |
 | L4          |    1.16.0    | https://github.com/STMicroelectronics/STM32CubeL4 |
 | L5          |    1.3.0     | https://github.com/STMicroelectronics/STM32CubeL5 |