ARM: shmobile: Enable fixed voltage regulator in shmobile_defconfig

This is selected by MACH_MARZEN which is enabled in shmobile_defconfig,
however, MACH_MARZEN is going away along with the board code it enables.

Acked-by: Magnus Damm <damm@opensource.se>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/configs/shmobile_defconfig

@@ -122,6 +122,7 @@ CONFIG_WATCHDOG=y
 CONFIG_DA9063_WATCHDOG=y
 CONFIG_MFD_AS3711=y
 CONFIG_MFD_DA9063=y
+CONFIG_REGULATOR_FIXED_VOLTAGE=y
 CONFIG_REGULATOR_AS3711=y
 CONFIG_REGULATOR_DA9210=y
 CONFIG_REGULATOR_GPIO=y