[PATCH] Teach gxemul yamon about clock discovery

[Bruce M Simpson]

Hi,

NetBSD has code which calibrates their DELAY() using the on-chip counter 
(as our code tries to do). However the YAMON monitor has a SYSCON read 
object which exports the board clock info via their API.

This patch teaches the GXemul YAMON prom emulation to export the 
configured CPU clock in the virtual machine to the host OS:
    http://people.freebsd.org/~bms/dump/gxemul-clockfreq-yamon.diff

I tested this with NetBSD-3.1 for evbmips malta.

I previously hacked a patch which did this via environment variables. A 
similar patch may be necessary for CFE or PMON firmware.

Regards,
BMS