lmb: Treat a region which is a subset as equal

In various cases logical memory blocks are coalesced; As a result doing
a strict check whether memory blocks are the same doesn't necessarily
work as a previous addition of a given block might have been merged into
a bigger block.

Fix this by considering a block is already registered if it's a pure
subset of one of the existing blocks.

Signed-off-by: Sjoerd Simons <sjoerd@collabora.com>
diff --git a/lib/lmb.c b/lib/lmb.c
index f447c63..2444b2a 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -247,8 +247,10 @@
 		phys_addr_t rgnbase = rgn->region[i].base;
 		phys_size_t rgnsize = rgn->region[i].size;
 		phys_size_t rgnflags = rgn->region[i].flags;
+		phys_addr_t end = base + size - 1;
+		phys_addr_t rgnend = rgnbase + rgnsize - 1;
 
-		if (rgnbase == base && rgnsize == size) {
+		if (rgnbase <= base && end <= rgnend) {
 			if (flags == rgnflags)
 				/* Already have this region, so we're done */
 				return 0;