commonlib/region: Turn addrspace_32bit into a more official API

We had the addrspace_32bit rdev in prog_loaders.c for a while to help
represent memory ranges as an rdev, and we've found it useful for a
couple of things that have nothing to do with program loading. This
patch moves the concept straight into commonlib/region.c so it is no
longer anchored in such a weird place, and easier to use in unit tests.
Also expand the concept to the whole address space (there's no real need
to restrict it to 32 bits in 64-bit environments) and introduce an
rdev_chain_mem() helper function to make it a bit easier to use. Replace
some direct uses of struct mem_region_device with this new API where it
seems to make sense.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: Ie4c763b77f77d227768556a9528681d771a08dca
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52533
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/lib/fmap.c b/src/lib/fmap.c
index 418e715..254d787 100644
--- a/src/lib/fmap.c
+++ b/src/lib/fmap.c
@@ -16,7 +16,7 @@
  */
 
 static int fmap_print_once;
-static struct mem_region_device fmap_cache;
+static struct region_device fmap_cache;
 
 #define print_once(...) do { \
 		if (!fmap_print_once) \
@@ -53,7 +53,7 @@
 	fmap_print_once = 1;
 }
 
-static void setup_preram_cache(struct mem_region_device *cache_mrdev)
+static void setup_preram_cache(struct region_device *cache_rdev)
 {
 	if (CONFIG(NO_FMAP_CACHE))
 		return;
@@ -99,7 +99,7 @@
 	report(fmap);
 
 register_cache:
-	mem_region_device_ro_init(cache_mrdev, fmap, FMAP_SIZE);
+	rdev_chain_mem(cache_rdev, fmap, FMAP_SIZE);
 }
 
 static int find_fmap_directory(struct region_device *fmrd)
@@ -109,10 +109,10 @@
 	size_t offset = FMAP_OFFSET;
 
 	/* Try FMAP cache first */
-	if (!region_device_sz(&fmap_cache.rdev))
+	if (!region_device_sz(&fmap_cache))
 		setup_preram_cache(&fmap_cache);
-	if (region_device_sz(&fmap_cache.rdev))
-		return rdev_chain_full(fmrd, &fmap_cache.rdev);
+	if (region_device_sz(&fmap_cache))
+		return rdev_chain_full(fmrd, &fmap_cache);
 
 	boot_device_init();
 	boot = boot_device_ro();
@@ -281,7 +281,7 @@
 	if (!e)
 		return;
 
-	mem_region_device_ro_init(&fmap_cache, cbmem_entry_start(e), cbmem_entry_size(e));
+	rdev_chain_mem(&fmap_cache, cbmem_entry_start(e), cbmem_entry_size(e));
 }
 
 /*