[LIB] Updated to newest libopencm3
[BUILD] Don't throw error on already cleaned output
FIX: u{8,16,32} -> uint{8,16,32}_t to be compatible with new library

The use of u8, u16, u32 has been deprecated in libopencm3.
Update it with standard uint8_t, uint16_t, uint32_t types
FIX: FLASH_* collision with libopencm3 definitions

Resolve collision to FLASH_* from the libopencm3 by adding STM32F1_ prefix to the L1's
FIX: usbd_init compatibility fix

Updated compatibility with libopencm3 commit 113e5c22e6390ba072148315e83a5faa5ff7ce86