microblaze: Enable KGDB in defconfig

Enable KGDB in defconfig to be sure that support
is regularly compiled.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/microblaze/configs/mmu_defconfig b/arch/microblaze/configs/mmu_defconfig
index 3649a8b..deaf45a 100644
--- a/arch/microblaze/configs/mmu_defconfig
+++ b/arch/microblaze/configs/mmu_defconfig
@@ -1,4 +1,3 @@
-CONFIG_EXPERIMENTAL=y
 CONFIG_SYSVIPC=y
 CONFIG_POSIX_MQUEUE=y
 CONFIG_FHANDLE=y
@@ -81,6 +80,9 @@
 CONFIG_DEBUG_SLAB=y
 CONFIG_DEBUG_SPINLOCK=y
 CONFIG_DEBUG_INFO=y
+CONFIG_KGDB=y
+CONFIG_KGDB_TESTS=y
+CONFIG_KGDB_KDB=y
 CONFIG_EARLY_PRINTK=y
 CONFIG_KEYS=y
 CONFIG_ENCRYPTED_KEYS=y