ARM: shmobile: fix platsmp.c build when ARCH_SH73A0=n

Fix build error in the case of SMP=y but ARCH_SH73A0=n
introduced by:

9601e873 ARM: shmobile: fix smp build

The use of of_machine_is_compatible() will link in the
the SoC-specific symbols:
"sh73a0_get_core_count", "sh73a0_smp_prepare_cpus",
"sh73a0_secondary_init" and "sh73a0_boot_secondary".

This patch adds an ugly #ifdef wrapper as a stop-gap
solution.
Signed-off-by: Magnus Damm <damm@opensource.se>
Tested-by: Tested-by: Simon Horman <horms@verge.net.au>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-shmobile/platsmp.c

@@ -22,8 +22,13 @@
 #include <mach/common.h>
 #include <mach/emev2.h>
 
+#ifdef CONFIG_ARCH_SH73A0
 #define is_sh73a0() (machine_is_ag5evm() || machine_is_kota2() || \
 			of_machine_is_compatible("renesas,sh73a0"))
+#else
+#define is_sh73a0() (0)
+#endif
+
 #define is_r8a7779() machine_is_marzen()
 
 #ifdef CONFIG_ARCH_EMEV2