ARM: at91/defconfig: sama5: add CONFIG_FHANDLE

CONFIG_FHANDLE is listed as a mandatory kernel option for systemd. So
explicitly enable it to allow easy use of systemd userspace.
Reported-by: Marek Vasut <marex@denx.de>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/configs/sama5_defconfig

 # CONFIG_LOCALVERSION_AUTO is not set
 # CONFIG_SWAP is not set
 CONFIG_SYSVIPC=y
+CONFIG_FHANDLE=y
 CONFIG_IRQ_DOMAIN_DEBUG=y
 CONFIG_LOG_BUF_SHIFT=14
 CONFIG_CGROUPS=y