kconfig: arm: move "armv8" define to arch/arm/Kconfig

Commit 2e07c249a6 (kconfig: arm: introduce symbol for ARM CPUs)
collected the default values of CONFIG_SYS_CPU into arch/arm/Kconfig.

This commit moves "armv8" to there for consistency.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Georges Savoundararadj <savoundg@gmail.com>

arch/arm/Kconfig

@@ -49,6 +49,7 @@ config SYS_CPU
         default "armv7" if CPU_V7
         default "pxa" if CPU_PXA
         default "sa1100" if CPU_SA1100
+	default "armv8" if ARM64
 
 choice
 	prompt "Target select"
@@ -778,8 +779,6 @@ config ARCH_UNIPHIER
 
 endchoice
 
-source "arch/arm/cpu/armv8/Kconfig"
-
 source "arch/arm/cpu/arm926ejs/davinci/Kconfig"
 
 source "arch/arm/cpu/armv7/exynos/Kconfig"

arch/arm/cpu/armv8/Kconfig

@@ -1,6 +0,0 @@
-if ARM64
-
-config SYS_CPU
-	default "armv8"
-
-endif