imx-common: introduce is_mx6ull

Introduce is_mx6ull macro.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>

arch/arm/include/asm/imx-common/sys_proto.h

@@ -33,6 +33,7 @@
 #define is_mx6sx() (is_cpu_type(MXC_CPU_MX6SX))
 #define is_mx6sl() (is_cpu_type(MXC_CPU_MX6SL))
 #define is_mx6ul() (is_cpu_type(MXC_CPU_MX6UL))
+#define is_mx6ull() (is_cpu_type(MXC_CPU_MX6ULL))
 
 u32 get_nr_cpus(void);
 u32 get_cpu_rev(void);