tree 3035dfb4e4aca90d649eb3d83fc40e6c50ae9c24
parent 0c3533fc0915d0d4e43f740f4ea739e51781dd88
author Kévin Redon <kredon@sysmocom.de> 1556193306 +0200
committer Kévin Redon <kredon@sysmocom.de> 1557409598 +0200

output 50 MHz for RMII

in hardware revision 2 the Ethernet PHY RMII_CLOCK input clock is
connected to the MCU pin PA10.
GCLK4 of the MCU now outputs the required 50 MHz clock on this pin.
the same clock is re-used for UART debug to generate the 921600
bps baud rate.

Change-Id: Id3a3dee15c3986536b0623d0f39ca62e94acd1fd