coreboot: add region infrastructure

The region infrastructure provides a means of abstracting
access to different types of storage such as SPI flash, MMC,
or just plain memory. The regions are represented by
region devices which can be chained together forming subregions
of the larger region. This allows the call sites to be agnostic
about the implementations behind the regions. Additionally, this
prepares for a cleaner API for CBFS accesses.

Change-Id: I803f97567ef0505691a69975c282fde1215ea6da
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9128
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/lib/Makefile.inc

@@ -29,6 +29,7 @@ bootblock-$(CONFIG_COLLECT_TIMESTAMPS) += timestamp.c
 bootblock-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c
 bootblock-y += memchr.c
 bootblock-y += memcmp.c
+bootblock-y += region.c
 
 verstage-y += prog_ops.c
 verstage-y += delay.c
@@ -37,6 +38,7 @@ verstage-y += cbfs_core.c
 verstage-y += halt.c
 verstage-y += memcmp.c
 verstage-$(CONFIG_COLLECT_TIMESTAMPS) += timestamp.c
+verstage-y += region.c
 verstage-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c
 verstage-$(CONFIG_COMMON_CBFS_SPI_WRAPPER) += cbfs_spi.c
 
@@ -132,6 +134,8 @@ ramstage-$(CONFIG_RELOCATABLE_RAMSTAGE) += cbmem_stage_cache.c
 romstage-$(CONFIG_RELOCATABLE_RAMSTAGE) += cbmem_stage_cache.c
 endif
 
+romstage-y += region.c
+ramstage-y += region.c
 
 smm-y += cbfs.c cbfs_core.c memcmp.c
 smm-$(CONFIG_COMPILER_GCC) += gcc.c