Blackfin: BF51x: fix L1 Instruction SRAM size

The BF51x's Instruction SRAM is 32kB, not 48kB.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

arch/blackfin/mach-bf518/include/mach/mem_map.h

@@ -41,7 +41,7 @@
 #define L1_DATA_A_START		0xFF800000
 #define L1_DATA_B_START		0xFF900000
 
-#define L1_CODE_LENGTH		0xC000
+#define L1_CODE_LENGTH		0x8000
 
 #ifdef CONFIG_BFIN_DCACHE