Eugen Hristev authored Aug 03, 2018 and Tom Rini committed Aug 13, 2018

In case the slow clock is not properly configured, the UTMI clock
cannot lock the PLL, because UPLLCOUNT will "wait X slow clock cycles".
In this case U-boot will loop indefinitely.
Added a timeout in this case, to start U-boot even if UTMI clock is
not enabled, so the user can use different media if needed, or investigate.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>