ARM: vexpress: Add fixed regulator for SMSC

SMSC driver requires "vdd33a" and "vddvario" regulator supplies now.

Add fixed regulator describing 3V3 power line (in both motherboard's
Device Trees and the non-DT code) and force fixed regulator config
option if regulators framework is enabled.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 6374a08..cb15fca 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -318,6 +318,7 @@
 	select NO_IOPORT
 	select PLAT_VERSATILE
 	select PLAT_VERSATILE_CLCD
+	select REGULATOR_FIXED_VOLTAGE if REGULATOR
 	help
 	  This enables support for the ARM Ltd Versatile Express boards.