parisc: enable DEVTMPFS, DEVTMPFS_MOUNT and BLK_DEV_INITRD in defconfigs

Latest udev requires that DEVTMPFS and DEVTMPFS_MOUNT are enabled, else
initrd will fail to find root filesystem. Enable missing BLK_DEV_INITRD
for B180 and C3000 machines.

Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/arch/parisc/configs/a500_defconfig b/arch/parisc/configs/a500_defconfig
index b647b18..9002532 100644
--- a/arch/parisc/configs/a500_defconfig
+++ b/arch/parisc/configs/a500_defconfig
@@ -79,6 +79,8 @@
 CONFIG_LLC2=m
 CONFIG_NET_PKTGEN=m
 CONFIG_UEVENT_HELPER_PATH="/sbin/hotplug"
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
 # CONFIG_STANDALONE is not set
 # CONFIG_PREVENT_FIRMWARE_BUILD is not set
 CONFIG_BLK_DEV_UMEM=m