ARM: l2c: fix dependencies on PL310 errata symbols

A number of configurations spit out warnings similar to:

warning: (SOC_IMX6 && SOC_VF610 && ARCH_OMAP4) selects PL310_ERRATA_588369 which has unmet direct dependencies (CACHE_L2X0)
warning: (SOC_IMX6 && SOC_VF610 && ARCH_OMAP4) selects PL310_ERRATA_727915 which has unmet direct dependencies (CACHE_L2X0)

Clean up the dependencies here:
* PL310 symbols should only be selected when CACHE_L2X0 is enabled.
* Since the cache-l2x0 code detects PL310 presence at runtime, and we will
  eventually get rid of CACHE_PL310, surround these errata options with an
  if CACHE_L2X0 conditional rather than repeating the dependency against
  each.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-ux500/Kconfig b/arch/arm/mach-ux500/Kconfig
index b41a42d..86f5372 100644
--- a/arch/arm/mach-ux500/Kconfig
+++ b/arch/arm/mach-ux500/Kconfig
@@ -16,7 +16,7 @@
 	select PINCTRL
 	select PINCTRL_ABX500
 	select PINCTRL_NOMADIK
-	select PL310_ERRATA_753970 if CACHE_PL310
+	select PL310_ERRATA_753970 if CACHE_L2X0
 	help
 	  Support for ST-Ericsson's Ux500 architecture