ARM: mmp/mmp2: fix cpu_is_mmp2() on mmp2-dt

cpu_is_mmp2() was equivalent to cpu_is_pj4(), wouldn't be correct for
multiplatform kernels. Fix it by also considering mmp_chip_id, as is
done for cpu_is_pxa168() and cpu_is_pxa910() above.

Moreover, it is only available with CONFIG_CPU_MMP2 and thus doesn't work
on DT-based MMP2 machines. Enable it on CONFIG_MACH_MMP2_DT too.

Note: CONFIG_CPU_MMP2 is only used for machines that use board files
instead of DT. It should perhaps be renamed. I'm not doing it now, because
I don't have a better idea.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm/mach-mmp/cputype.h

@@ -44,10 +44,12 @@ static inline int cpu_is_pxa910(void)
 #define cpu_is_pxa910()	(0)
 #endif
 
-#ifdef CONFIG_CPU_MMP2
+#if defined(CONFIG_CPU_MMP2) || defined(CONFIG_MACH_MMP2_DT)
 static inline int cpu_is_mmp2(void)
 {
-	return (((read_cpuid_id() >> 8) & 0xff) == 0x58);
+	return (((read_cpuid_id() >> 8) & 0xff) == 0x58) &&
+		(((mmp_chip_id & 0xfff) == 0x410) ||
+		 ((mmp_chip_id & 0xfff) == 0x610));
 }
 #else
 #define cpu_is_mmp2()	(0)