K 10
svn:author
V 4
manu
K 8
svn:date
V 27
2018-07-31T20:50:50.170493Z
K 7
svn:log
V 301
ofw_cpu: Add support for getting cpu clock via clock property

Nominal Mhz is either expressed via the clock-frequency property
or can be get via the clock property that holds the cpu clock.
Add support for the later.

Reviewed by:	nwhitehorn
Differential Revision:	https://reviews.freebsd.org/D16346

END