ARM: OMAP2+: Initialize SoC PM later

There's no need to probe devices until at module_init time and we
currently have at least PM trying to use I2C for PMICs early on.

As only a part of the SoC init_early is SoC specific, we only need to call
the SoC specific PM init function. And we can modify omap2_common_pm_late_init()
so it becomes a late_initcall().

Note that this changes am335x to call omap2_clk_enable_autoidle_all() that
seems to be missing currently.

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