ARM: SAMSUNG: Fix mask value for S5P64X0 CPU IDs

The current value for S5P64XX_CPU_MASK does not include the necessary
bits, which causes detection failure.
Signed-off-by: NAjay Kumar <ajaykumar.rs@samsung.com>
[kgene.kim@samsung.com: changed the value]
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

arch/arm/plat-samsung/include/plat/cpu.h

@@ -30,7 +30,7 @@ extern unsigned long samsung_cpu_id;
 
 #define S5P6440_CPU_ID		0x56440000
 #define S5P6450_CPU_ID		0x36450000
-#define S5P64XX_CPU_MASK	0x1FF40000
+#define S5P64XX_CPU_MASK	0xFFFFF000
 
 #define S5PC100_CPU_ID		0x43100000
 #define S5PC100_CPU_MASK	0xFFFFF000