ARM: OMAP: Remove definition cpu_is_omap4430()

The definition cpu_is_omap4430() always returns 0 even when CONFIG_ARCH_OMAP4
is enabled. This macro should be removed and the macro cpu_is_omap443x() should
be used where needed for OMAP4430 devices.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>