soc: xilinx: Create folder structure for soc specific drivers

Create directory structure with Makefile/Kconfig for adding xilinx soc
specific drivers.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/drivers/soc/xilinx/Makefile b/drivers/soc/xilinx/Makefile
new file mode 100644
index 0000000..f66554c
--- /dev/null
+++ b/drivers/soc/xilinx/Makefile
@@ -0,0 +1 @@
+# SPDX-License-Identifier: GPL-2.0