OMAP hwmod: add hwmod class support

Add support for categorizing and iterating over hardware IP blocks by
the "class" of the IP block.  The class is the type of the IP block:
e.g., "timer", "timer1ms", etc.  Move the OCP_SYSCONFIG/SYSSTATUS data
from the struct omap_hwmod into the struct omap_hwmod_class, since
it's expected to stay consistent for each class.  While here, fix some
comments.

The hwmod_class structures in this patch were designed and proposed by
Benoît Cousson <b-cousson@ti.com> and were refined in a discussion
between Thara Gopinath <thara@ti.com>, Kevin Hilman
<khilman@deeprootsystems.com>, and myself.

This patch uses WARN() lines that are longer than 80 characters, as
Kevin noted a broader lkml consensus to increase greppability by
keeping the messages all on one line.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Benoît Cousson <b-cousson@ti.com>
Cc: Thara Gopinath <thara@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-omap2/Makefile

@@ -5,15 +5,16 @@
 # Common support
 obj-y := id.o io.o control.o mux.o devices.o serial.o gpmc.o timer-gp.o
 
-omap-2-3-common				= irq.o sdrc.o omap_hwmod.o \
+omap-2-3-common				= irq.o sdrc.o
+hwmod-common				= omap_hwmod.o \
 					  omap_hwmod_common_data.o
 prcm-common				= prcm.o powerdomain.o
 clock-common				= clock.o clock_common_data.o \
 					  clockdomain.o clkt_dpll.o \
 					  clkt_clksel.o
 
-obj-$(CONFIG_ARCH_OMAP2) += $(omap-2-3-common) $(prcm-common)
-obj-$(CONFIG_ARCH_OMAP3) += $(omap-2-3-common) $(prcm-common)
+obj-$(CONFIG_ARCH_OMAP2) += $(omap-2-3-common) $(prcm-common) $(hwmod-common)
+obj-$(CONFIG_ARCH_OMAP3) += $(omap-2-3-common) $(prcm-common) $(hwmod-common)
 obj-$(CONFIG_ARCH_OMAP4) += $(prcm-common)
 
 obj-$(CONFIG_OMAP_MCBSP) += mcbsp.o