OMAP4: Fix cpu detection

This patch fixes the OMAP4430 cpu detection. The IC rev detection is
done with hawkeye and rev. Note that rev does not map directly to
defined processor revision numbers as ES1.0 uses value 0.It also fixes
the SCM base address to read the correct ID_CODE register.

Also the cpu_is_omap44xx() and cpu_is_omap443x() correctly populated
instead of always being true

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