Each DPLL exists in its own powerdomain (cf 34xx TRM figure 4-18) and
clockdomain; so, create powerdomain and clockdomain structures for them.
Mark each DPLL clock as belonging to their respective DPLL clockdomain.
cf. 34xx TRM Table 4-27 (among other references).

linux-omap source commits are acdb6158 and
a8798a48.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>