region: publicize region_end() and add region_device_end()

Provide region_device_end() and make region_end() publically available
for use to match a pattern of open coding the offset + size calculation
for both struct region and struct region_device. Apply the use of the
helpers where the usage matches in the code.

Change-Id: Iaef5d007eef9a77f7f33b0e89298abef0197352d
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36689
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/commonlib/region.c

@@ -15,11 +15,6 @@
 #include <commonlib/region.h>
 #include <string.h>
 
-static inline size_t region_end(const struct region *r)
-{
-	return region_sz(r) + region_offset(r);
-}
-
 int region_is_subregion(const struct region *p, const struct region *c)
 {
 	if (region_offset(c) < region_offset(p))