arm64: Do not source kernel/time/Kconfig explicitly

As per commit 764e0da1 (timers: Fixup the Kconfig consolidation
fallout), init/Kconfig already includes kernel/time/Kconfig, so no need
to do it explicitly for arm64.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/Kconfig

@@ -122,8 +122,6 @@ endmenu
 
 menu "Kernel Features"
 
-source "kernel/time/Kconfig"
-
 config ARM64_64K_PAGES
 	bool "Enable 64KB pages support"
 	help