[U-Boot-Users] UBoot hangs in serial_putc on mpc8xx

[nyet at mrv.com]

The 8xx BRG code is has an interesting side effect if the cpu clock
rate is not properly detected... the divisor will overflow the allowed
bitwidth and an invalid value will get put brgc1

Hardcode CONFIG_8xx_GCLK_FREQ and/or brgc1 in speed.c and serial.c

I am working on putting together a fairly extensive 8xx patch to address
this and many other problems.