soc: r9a06g032: don't build SMP files for non-SMP config

soc: r9a06g032: don't build SMP files for non-SMP config

Without CONFIG_SMP, we get a build failure:

In file included from include/linux/byteorder/little_endian.h:5,
                 from arch/arm/include/uapi/asm/byteorder.h:22,
                 from include/asm-generic/bitops/le.h:6,
                 from arch/arm/include/asm/bitops.h:342,
                 from include/linux/bitops.h:18,
                 from include/linux/kernel.h:11,
                 from include/asm-generic/bug.h:18,
                 from arch/arm/include/asm/bug.h:60,
                 from include/linux/bug.h:5,
                 from include/linux/io.h:23,
                 from drivers/soc/renesas/r9a06g032-smp.c:11:
drivers/soc/renesas/r9a06g032-smp.c: In function 'r9a06g032_smp_boot_secondary':
drivers/soc/renesas/r9a06g032-smp.c:43:21: error: 'secondary_startup' undeclared (first use in this function)
  writel(__pa_symbol(secondary_startup), cpu_bootaddr);
                     ^~~~~~~~~~~~~~~~~

This makes the compilation of that file conditional on SMP support.
It would probably be better for consistency to leave that file
in arch/arm/mach-shmobile/, matching what we do for all other smp
operations.

Fixes: cde4f86f9249 ("arm: shmobile: Add the R9A06G032 SMP enabler driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>