ARM: OMAP2+: Add fixed regulator to omap2plus_defconfig

We do not have REGULATOR_FIXED selected if no boards are selected
and we boot with device tree. This can cause various devices to
fail.
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/configs/omap2plus_defconfig

@@ -173,6 +173,7 @@ CONFIG_MFD_PALMAS=y
 CONFIG_MFD_TPS65217=y
 CONFIG_MFD_TPS65910=y
 CONFIG_TWL6040_CORE=y
+CONFIG_REGULATOR_FIXED_VOLTAGE=y
 CONFIG_REGULATOR_PALMAS=y
 CONFIG_REGULATOR_TPS65023=y
 CONFIG_REGULATOR_TPS6507X=y