feat(doe): add PCIe DOE tests

This patch adds PCIe DOE tests for
- DOE discovery protocol
- SPDM get version
To build this test suite use 'TEST=pcie-doe'
option.

The spdm.h is imported from https://github.com/DMTF/libspdm
project.

Change-Id: I8db1048d01b4f8061d8a4ddccc198159ed61e6b7
Signed-off-by: AlexeiFedorov <Alexei.Fedorov@arm.com>
diff --git a/lib/pcie/pcie.c b/lib/pcie/pcie.c
index 22464c2..c3906d5 100644
--- a/lib/pcie/pcie.c
+++ b/lib/pcie/pcie.c
@@ -5,9 +5,10 @@
  */
 
 #include <assert.h>
+#include <stddef.h>
+
 #include <debug.h>
 #include <mmio.h>
-#include <stddef.h>
 #include <pcie.h>
 #include <pcie_spec.h>
 #include <tftf_lib.h>
diff --git a/lib/pcie/pcie_doe.c b/lib/pcie/pcie_doe.c
index 7cdbd66..3c6819c 100644
--- a/lib/pcie/pcie_doe.c
+++ b/lib/pcie/pcie_doe.c
@@ -5,10 +5,11 @@
  *
  */
 
-#include <stdlib.h>
-#include <debug.h>
 #include <errno.h>
+#include <stdlib.h>
 #include <string.h>
+
+#include <debug.h>
 #include <pcie.h>
 #include <pcie_doe.h>
 #include <tftf_lib.h>