spl: Use map_sysmem where appropriate

All "physical" addresses in SPL must be converted to virtual addresses
before access in order for sandbox to work. Add some calls to map_sysmem in
appropriate places. We do not generally call unmap_sysmem, since we need
the image memory to still be mapped when we jump to the image. This doesn't
matter at the moment since unmap_sysmem is a no-op.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/common/spl/spl_ext.c b/common/spl/spl_ext.c
index 902564a..af836ca 100644
--- a/common/spl/spl_ext.c
+++ b/common/spl/spl_ext.c
@@ -2,6 +2,7 @@
 
 #include <common.h>
 #include <env.h>
+#include <mapmem.h>
 #include <part.h>
 #include <spl.h>
 #include <asm/u-boot.h>
@@ -53,7 +54,8 @@
 		goto end;
 	}
 
-	err = ext4fs_read((char *)spl_image->load_addr, 0, filelen, &actlen);
+	err = ext4fs_read(map_sysmem(spl_image->load_addr, filelen), 0, filelen,
+			  &actlen);
 
 end:
 #ifdef CONFIG_SPL_LIBCOMMON_SUPPORT