layerscape: use the lmb API's to add RAM memory

The EFI memory allocations are now being done through the LMB module,
and hence the memory map is maintained by the LMB module. Use the
lmb_arch_add_memory() API function to add the usable RAM memory to the
LMB's memory map.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
diff --git a/lib/Kconfig b/lib/Kconfig
index 3d2011a..b6b8b8d 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -1122,6 +1122,7 @@
 config LMB_ARCH_MEM_MAP
 	bool "Add an architecture specific memory map"
 	depends on LMB
+	default y if FSL_LAYERSCAPE
 	help
 	  Some architectures have special or unique aspects which need
 	  consideration when adding memory ranges to the list of available