xilinx: r5: Disable EFI loader

Xilinx ZynqMP R5 configuration is quite minimal and there is no reason to
enable EFI for it.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/xilinx_zynqmp_r5_defconfig b/configs/xilinx_zynqmp_r5_defconfig
index 713418e..1c6fc73 100644
--- a/configs/xilinx_zynqmp_r5_defconfig
+++ b/configs/xilinx_zynqmp_r5_defconfig
@@ -18,3 +18,4 @@
 CONFIG_ZYNQ_SERIAL=y
 CONFIG_TIMER=y
 CONFIG_CADENCE_TTC_TIMER=y
+# CONFIG_EFI_LOADER is not set