ARM: OMAP: move plat-omap/include/plat/sdrc.h into mach-omap2/sdrc.h

Remove arch/arm/plat-omap/include/plat/sdrc.h by folding its contents
into arch/arm/mach-omap2/sdrc.h.  The objective is to assist Tony in
cleaning out arch/arm/plat-omap/, as his upstreams request.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>
[tony@atomide.com: updated to remove rotate macros]
Signed-off-by: Tony Lindgren <tony@atomide.com>