Remove hip-hcc codes: Part four

Remove __HCC__, __HCC_ONLY__, __HCC_CPP__, __HCC_C__,
__HCC_OR_HIP_CLANG__, __HIP_ROCclr__ and their guarded codes.

Remove Hcc codes from directed_tests and samples.

Remove __HIP_PLATFORM_HCC__ and __HIP_PLATFORM_NVCC__ from
some files where they are not necessary.

Add deprecation notice.

Change-Id: I1ae467eafd749d6c25bca204c1724b026be21fce

include/hip/hip_bfloat16.h

@@ -29,7 +29,7 @@
 #ifndef _HIP_BFLOAT16_H_
 #define _HIP_BFLOAT16_H_
 
-#if __cplusplus < 201103L || (!defined(__HCC__) && !defined(__HIPCC__))
+#if __cplusplus < 201103L || !defined(__HIPCC__)
 
 // If this is a C compiler, C++ compiler below C++11, or a host-only compiler, we only
 // include a minimal definition of hip_bfloat16
@@ -41,7 +41,7 @@ typedef struct
     uint16_t data;
 } hip_bfloat16;
 
-#else // __cplusplus < 201103L || (!defined(__HCC__) && !defined(__HIPCC__))
+#else // __cplusplus < 201103L || !defined(__HIPCC__)
 
 #include <cmath>
 #include <cstddef>
@@ -275,6 +275,6 @@ namespace std
     }
 }
 
-#endif // __cplusplus < 201103L || (!defined(__HCC__) && !defined(__HIPCC__))
+#endif // __cplusplus < 201103L || !defined(__HIPCC__)
 
 #endif // _HIP_BFLOAT16_H_