ARM: OMAP3: Fix hardware detection for omap3630 when booted with device tree

SoC family definitions at the moment are reactive to board needs
as a result, beagle-xm would matchup with ti,omap3 which invokes
omap3430_init_early instead of omap3630_init_early. Obviously, this is
the wrong behavior.

With clock node dts conversion, we get the following warnings before
system hangs as a result and 3630 based platforms fails to boot
(uart4 clocks are only present in OMAP3630 and not present in
OMAP3430):

...
omap_hwmod: uart4: cannot clk_get main_clk uart4_fck
omap_hwmod: uart4: cannot _init_clocks

WARNING: CPU: 0 PID: 1 at arch/arm/mach-omap2/omap_hwmod.c:2434
_init+0x6c/0x80()
omap_hwmod: uart4: couldn't init clocks
...

WARNING: CPU: 0 PID: 1 at arch/arm/mach-omap2/omap_hwmod.c:2126
_enable+0x254/0x280()
omap_hwmod: timer12: enabled state can only be entered from
initialized, idle, or disabled state
...

WARNING: CPU: 0 PID: 46 at arch/arm/mach-omap2/omap_hwmod.c:2224
_idle+0xd4/0xf8()
omap_hwmod: timer12: idle state can only be entered from enabled state

WARNING: CPU: 0 PID: 1 at arch/arm/mach-omap2/omap_hwmod.c:2126
_enable+0x254/0x280()
omap_hwmod: uart4: enabled state can only be entered from
initialized, idle, or disabled state

So, add specific compatiblity for 3630 to allow match for Beagle-XM
platform.

Signed-off-by: Nishanth Menon <nm@ti.com>
[tony@atomide.com: left out ti,omap343x, updated comments]
Signed-off-by: Tony Lindgren <tony@atomide.com>