ARM: shmobile: Restrict TWD support to SoCs that have it

Currently support for the ARM Timer and Watchdog Unit is included
unconditionally, while only some Renesas multicore Cortex-A9 SoCs have
a TWD.

This decreases kernel image size by ca. 2 KiB on SoCs without a TWD.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/mach-shmobile/Kconfig

@@ -30,7 +30,6 @@ menuconfig ARCH_RENESAS
 	depends on ARCH_MULTI_V7 && MMU
 	select ARM_GIC
 	select GPIOLIB
-	select HAVE_ARM_TWD if SMP
 	select NO_IOPORT_MAP
 	select PINCTRL
 	select SOC_BUS
@@ -95,6 +94,7 @@ config ARCH_R8A7778
 config ARCH_R8A7779
 	bool "R-Car H1 (R8A77790)"
 	select HAVE_ARM_SCU if SMP
+	select HAVE_ARM_TWD if SMP
 	select ARCH_RCAR_GEN1
 
 config ARCH_R8A7790
@@ -137,5 +137,6 @@ config ARCH_SH73A0
 	bool "SH-Mobile AG5 (R8A73A00)"
 	select ARCH_RMOBILE
 	select HAVE_ARM_SCU if SMP
+	select HAVE_ARM_TWD if SMP
 	select RENESAS_INTC_IRQPIN
 endif