ARM: shmobile: Remove ARCH_SHMOBILE_MULTI

The migration from ARCH_SHMOBILE_MULTI to ARCH_RENESAS has been
completed in v4.12 by commit 9ed2d4bc ("ARM: dts: renesas:
Switch from ARCH_SHMOBILE_MULTI to ARCH_RENESAS"), so the
ARCH_SHMOBILE_MULTI symbol can be removed.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

arch/arm/mach-shmobile/Kconfig

 config ARCH_SHMOBILE
 	bool
 
-config ARCH_SHMOBILE_MULTI
-	bool
-
 config PM_RMOBILE
 	bool
 	select PM
@@ -34,7 +31,6 @@ menuconfig ARCH_RENESAS
 	depends on ARCH_MULTI_V7 && MMU
 	select ARCH_DMA_ADDR_T_64BIT if ARM_LPAE
 	select ARCH_SHMOBILE
-	select ARCH_SHMOBILE_MULTI
 	select ARM_GIC
 	select GPIOLIB
 	select HAVE_ARM_SCU if SMP