fpga: zynqmp: support loading encrypted bitfiles

Add supporting new compatible string "u-boot,zynqmp-fpga-enc" to
handle loading encrypted bitfiles.

This feature requires encrypted FSBL, as according to UG1085:
"The CSU automatically locks out the AES key, stored in either BBRAM
 or eFUSEs, as a key source to the AES engine if the FSBL is not
 encrypted. This prevents using the BBRAM or eFUSE as the key source
 to the AES engine during run-time applications."

Signed-off-by: Adrian Fiergolski <adrian.fiergolski@fastree3d.com>
Co-developed-by: Oleksandr Suvorov <oleksandr.suvorov@foundries.io>
Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@foundries.io>
Tested-by: Adrian Fiergolski <adrian.fiergolski@fastree3d.com>
Link: https://lore.kernel.org/r/20220722141614.297383-14-oleksandr.suvorov@foundries.io
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/include/zynqmppl.h b/include/zynqmppl.h
index 87ccd2f..acf75a8 100644
--- a/include/zynqmppl.h
+++ b/include/zynqmppl.h
@@ -26,7 +26,9 @@
 extern struct xilinx_fpga_op zynqmp_op;
 
 #if CONFIG_IS_ENABLED(FPGA_LOAD_SECURE)
-#define ZYNQMP_FPGA_FLAGS	(FPGA_LEGACY | FPGA_XILINX_ZYNQMP_DDRAUTH)
+#define ZYNQMP_FPGA_FLAGS	(FPGA_LEGACY | \
+				 FPGA_XILINX_ZYNQMP_DDRAUTH | \
+				 FPGA_XILINX_ZYNQMP_ENC)
 #else
 #define ZYNQMP_FPGA_FLAGS	(FPGA_LEGACY)
 #endif