feat(usb): provide default vid/pid

Provided id:
  - Default USB CDC for all series with USB capabilities (0483:5740)
  - STLink VCP, only for ST manufactured boards which embedd one (0483:37xx)
  - DFU for default built-in bootloader or dedicated one (0483:df11 and other)
  - Specific USB id.

Note that vid.0/pid.0 have to be defined for each menu even if no USB
support to have the build.vid/pid properly defined in the platform.txt.
At least a FTDI is defined (ex: STLink VCP)

Signed-off-by: Frederic Pillon <frederic.pillon@st.com>

# Conflicts:
#	boards.txt

Author: fpistm