ARM: OMAP2+: Fix overwriting hwmod data with data from device tree

We have some device tree properties where the ti,hwmod have multiple
values:

am33xx.dtsi:	ti,hwmods = "tpcc", "tptc0", "tptc1", "tptc2";
am4372.dtsi:	ti,hwmods = "tpcc", "tptc0", "tptc1", "tptc2";
dra7.dtsi:	ti,hwmods = "l3_main_1", "l3_main_2";
omap3.dtsi:	ti,hwmods = "mcbsp2", "mcbsp2_sidetone";
omap3.dtsi:	ti,hwmods = "mcbsp3", "mcbsp3_sidetone";
omap4.dtsi:	ti,hwmods = "l3_main_1", "l3_main_2", "l3_main_3";
omap5.dtsi:	ti,hwmods = "l3_main_1", "l3_main_2", "l3_main_3";

That's not correct way of doing things in this case because these are
separate devices with their own address space, interrupts, SYSCONFIG
registers and can set their PM states independently.

So they should all be fixed up to be separate devices in the .dts files.

We also have the related data removed for at least omap4 in commit
3b9b1015

 (ARM: OMAP4: hwmod data: Clean up the data file), so
that data is wrongly initialized as null data.

So we need to fix two bugs:

1. We are only checking the first entry of the ti,hwmods property

   This means that we're only initializing the first hwmods entry
   instead of the ones listed in the ti,hwmods property.

2. We are only checking the child nodes, not the nodes themselves

   This means that anything listed at OCP level is currently just
   ignored and unitialized and at least the omap4 case, with the
   legacy data missing from the hwmod.

Fix both of the issues by using an index to the ti,hwmods property
and changing the hwmod lookup function to also check the current node
for ti,hwmods property instead of just the children.

While at it, let's also add some warnings for the bad data so it's
easier to fix.

Cc: "Benoît Cousson" <bcousson@baylibre.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>