ARM: imx_v6_v7_defconfig: enable EPD regulator needed for Kobo Clara 2e

Kobo Clara 2e revision b requires the JD9930/FP9931 regulator driver
for the EPD, so enable it.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Author: akemnade

arch/arm/configs/imx_v6_v7_defconfig

@@ -251,6 +251,7 @@ CONFIG_REGULATOR_DA9052=y
 CONFIG_REGULATOR_DA9062=y
 CONFIG_REGULATOR_DA9063=y
 CONFIG_REGULATOR_GPIO=y
+CONFIG_REGULATOR_FP9931=m
 CONFIG_REGULATOR_LTC3676=y
 CONFIG_REGULATOR_MC13783=y
 CONFIG_REGULATOR_MC13892=y