ARM: OMAP4: Add support for 4430 SDP

This patch updates the Makefile and Kconfig entries for OMAP4. The OMAP4430 SDP
board file supports only minimal set of drivers.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>