ARM: multi_v5_defconfig: Enable initramfs support

This makes it possible to automatically boot-test this defconfig with
kernelci.org.
Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/configs/multi_v5_defconfig

@@ -2,6 +2,7 @@ CONFIG_SYSVIPC=y
 CONFIG_NO_HZ=y
 CONFIG_HIGH_RES_TIMERS=y
 CONFIG_LOG_BUF_SHIFT=19
+CONFIG_BLK_DEV_INITRD=y
 CONFIG_PROFILING=y
 CONFIG_OPROFILE=y
 CONFIG_KPROBES=y