phal: Added extensions/phal folder

Added phal specific folder to keep all phal feature
based function in common place

Moved phal error specific source files to  extensions/phal

Tested: build verified.

Signed-off-by: Jayanth Othayoth <ojayanth@in.ibm.com>
Change-Id: Iabae2689444f355008802950a293e7c69cb19553
diff --git a/procedures/phal/start_host.cpp b/procedures/phal/start_host.cpp
index 152bd7e..d6b0b40 100644
--- a/procedures/phal/start_host.cpp
+++ b/procedures/phal/start_host.cpp
@@ -5,7 +5,7 @@
 
 #include "attributes_info.H"
 
-#include "phalerror/phal_error.hpp"
+#include "extensions/phal/phal_error.hpp"
 #include "procedures/phal/common_utils.hpp"
 #include "util.hpp"