ARM: OMAP2+: hwmod_core: improve the support for clkctrl clocks

This patch adds support for split memory ranges for clkctrl providers.
This is necessary to support the coming clockdomain based split of
clkctrl provider ranges, instead of the current CM instance based one.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>