OMAP2: cpu_is_omap2*: fix compile-time removal of unused code

Currently if omap2420 is defined but not omap2430, cpu_is_omap2430()
is still defined as a macro, instead of #define'd to zero.  This
results in conditional cpu_is_omap2430() code still being compiled,
and leads to possible compile/link errors.  In particular for hwmod
init.

To fix, add extra #ifdefs to CPU check macros to ensure that the
is_omap* macros are zero for each OMAP2 if they are not configured
into the kernel.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

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

@@ -167,10 +167,14 @@ IS_OMAP_SUBCLASS(443x, 0x443)
 #if defined(MULTI_OMAP2)
 # if defined(CONFIG_ARCH_OMAP2)
 #  undef  cpu_is_omap24xx
-#  undef  cpu_is_omap242x
-#  undef  cpu_is_omap243x
 #  define cpu_is_omap24xx()		is_omap24xx()
+# endif
+# if defined (CONFIG_ARCH_OMAP2420)
+#  undef  cpu_is_omap242x
 #  define cpu_is_omap242x()		is_omap242x()
+# endif
+# if defined (CONFIG_ARCH_OMAP2430)
+#  undef  cpu_is_omap243x
 #  define cpu_is_omap243x()		is_omap243x()
 # endif
 # if defined(CONFIG_ARCH_OMAP3)