Blackfin arch: make sure L2 start and length are always defined (fixes building on BF542)

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

arch/blackfin/mach-bf548/include/mach/mem_map.h

@@ -94,13 +94,13 @@
 #endif /*CONFIG_BFIN_DCACHE*/
 
 /* Level 2 Memory */
-#if !defined(CONFIG_BF542)
-# define L2_START          0xFEB00000
-# if defined(CONFIG_BF544)
+#define L2_START            0xFEB00000
+#if defined(CONFIG_BF542)
+# define L2_LENGTH          0
+#elif defined(CONFIG_BF544)
 # define L2_LENGTH          0x10000
-# else
+#else
 # define L2_LENGTH          0x20000
-# endif
 #endif
 
 /* Scratch Pad Memory */