ARM: OMAP2+: Prepare class allocation for dynamically allocated modules

For dynamically allocated sysconfig data we only need to allocate a new
class for the cases where the class is shared. For dynamically allocated
struct omap_hwmod we will always allocate a new class.

Let's add detection for when we need to allocate a new class by comparing
the class name against the module name. If they match, there's no need
to allocate a new calls as we don't have case of mixed platform data and
dts data initialized modules for the same class.

Let's also move the init of class data inside the spinlock.

Cc: Paul Walmsley <paul@pwsan.com>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>