clk: vexpress: Make the clock drivers directly available for arm64

The new arm64 architecture has no idea of platform or machine, so
it doesn't have to define ARCH_VEXPRESS configuration option at
all. To allow user to select the drivers at all, make it depend
on ARM64 as well.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/clk/Kconfig

@@ -42,7 +42,7 @@ config COMMON_CLK_WM831X
 
 config COMMON_CLK_VERSATILE
 	bool "Clock driver for ARM Reference designs"
-	depends on ARCH_INTEGRATOR || ARCH_REALVIEW || ARCH_VEXPRESS
+	depends on ARCH_INTEGRATOR || ARCH_REALVIEW || ARCH_VEXPRESS || ARM64
 	---help---
           Supports clocking on ARM Reference designs:
 	  - Integrator/AP and Integrator/CP