kfdtest: make p2ptest go through all gpus

Implement sDMA copy packet broadcast.

Each time sDMA will copy its local vram to sysbuf and next GPU's vram.
That will verify where the p2p link is broken.
Currently we just test push of p2p.

test result on 2 cpus, 4 gpus, numa enabled system.
[ RUN      ] KFDQMTest.P2PTest
[          ] Test 2 -> 3
[          ] PASS 2 -> 3
[          ] Test 3 -> 4
[          ] PASS 3 -> 4
[          ] Test 4 -> 5
[          ] PASS 4 -> 5
[          ] Test 5 -> 0
[          ] PASS 5 -> 0
[       OK ] KFDQMTest.P2PTest (190 ms)

Change-Id: Ie6fb2604109e39465b8a873b3bb42abc6259825a

tests/kfdtest/src/SDMAPacket.hpp

@@ -64,6 +64,7 @@ class SDMACopyDataPacket : public SDMAPacket {
  public:
     // this contructor will also init the packet, no need for adittional calls
     SDMACopyDataPacket(void *dest, void *src, unsigned int size);
+    SDMACopyDataPacket(void *const dst[], void *src, int n, unsigned int surfsize);
 
     virtual ~SDMACopyDataPacket(void);