arm: mvebu: Various mvebu clock fixes/improvements

[Thomas Petazzoni]

Andrew,

You'll find enclosed seven patches brigging fixes and improvements to
the CLK support on mvebu platforms. You can either squash them into
your current clk series if you intend to send a new version of it to
Jason, or forward the patches as follow-up patches to Jason after
reviewing.

In summary:

 * Patch 1 fixes a real problem: the gating clocks are not registered
   on Armada 370/XP.

 * Patch 2, 3, 5 and 6 are more cosmetic patches, but I think they are
   good to have.

 * Patch 4 implements a fix that we've been discussing: moving the
   Armada XP CPU clocks down to the individual armada-xp-mv78xxx.dtsi
   files.

 * Patch 7 fixes the references to the SATA clocks on Armada
   370/XP. Without this patch, Armada 370 currently hangs at boot when
   trying to initialize SATA.

Thanks,

Thomas