Fix: length for scatter loading should be in words not in bytes

Divide by 4 the length in bytes to get length in words as expected by
the CMSIS scatter loading implementation.

Change-Id: I5d239e13739a578bd61dc0b594e3453e8dcdab4d
diff --git a/targets/corstone-310/platform.ld b/targets/corstone-310/platform.ld
index 21c46b9..9d41f8f 100644
--- a/targets/corstone-310/platform.ld
+++ b/targets/corstone-310/platform.ld
@@ -216,7 +216,7 @@
 
     LONG (LOADADDR(.sram))
     LONG (ADDR(.sram))
-    LONG (SIZEOF(.sram))
+    LONG (SIZEOF(.sram) / 4)
 
     __copy_table_end__ = .;
   } > BRAM :rom_exec
@@ -227,10 +227,10 @@
     __zero_table_start__ = .;
 
     LONG (ADDR(.bss))
-    LONG (SIZEOF(.bss))
+    LONG (SIZEOF(.bss) / 4)
 
     LONG (ADDR(.sram.bss))
-    LONG (SIZEOF(.sram.bss))
+    LONG (SIZEOF(.sram.bss) / 4)
 
     __zero_table_end__ = .;
   } > BRAM :rom_exec