Port AES and RND to STM32 M0 + some improvements
arch/arm/src/stm32f0l0/stm32_rng.c: change the function names to use the stm32_rng prefix
arch/arm/src/stm32f0l0/stm32_usbdev.c: move HSI48 enable to stm32xx_rcc.c
arch/arm/src/stm32f0l0: add support for AES
arch/arm/src/stm32f0l0: add support for RND
arch/arm/src/stm32f0l0: add HSI48 support for L0
Approved-by: Gregory Nutt <gnutt@nuttx.org>