Added hipDeviceGetLimit api

1. hipDeviceGetLimit API for HCC path is added
2. Test for hipDeviceGetLimit API is added
3. The feature added only supports querying heap size
4. Corrected indents for malloc and free device functions
5. Removed redundant data structures
6. Added g_heap_malloc_size to store the heap size

Change-Id: If48d1b0ce9270e994f1c542cc283ddbb14746bbb


[ROCm/clr commit: e5325a1ab4]

projects/clr/hipamd/tests/src/deviceLib/hipTestDeviceLimit.cpp

@@ -0,0 +1,10 @@
+#include<hip/hip_runtime_api.h>
+#include<iostream>
+#include<assert.h>
+
+int main()
+{
+    size_t heap;
+    assert(hipSuccess == hipDeviceGetLimit(&heap, hipLimitMallocHeapSize));
+    assert(heap == 4194304);
+}