hipHostRegister and hipHostMalloc refactor.

Note hipHostMalloc (not hipHostAlloc or hipMallocHost).
 -  the hipHost* is used for all HIP APIs dealing with Host memory.
    (including hipHostMalloc, hipHostFree, hipHostRegister,
hipHostUnregister, hipHostGetFlags, hipHostGetDevicePointer).
  - hipMallocHost is consistent with "hipMalloc" for allocating device
    memory.  Enumerations hipHostMalloc* also used as optional
    flags parm to hipHostMalloc.

hipamd/util/vim/hip.vim

@@ -103,7 +103,13 @@ syn keyword hipFunctionName hipEventRecord
 syn keyword hipFunctionName hipEventSynchronize 
 syn keyword hipFunctionName hipFree 
 syn keyword hipFunctionName hipFreeArray 
-syn keyword hipFunctionName hipFreeHost  
+syn keyword hipFunctionName hipHostMalloc  
+syn keyword hipFunctionName hipHostFree  
+syn keyword hipFunctionName hipHostGetDevicePointer  
+syn keyword hipFunctionName hipHostGetFlags  
+syn keyword hipFunctionName hipHostRegister  
+syn keyword hipFunctionName hipHostUnregister  
+
 syn keyword hipFunctionName hipGetChannelDesc 
 syn keyword hipFunctionName hipGetDevice 
 syn keyword hipFunctionName hipGetDeviceCount 
@@ -165,6 +171,16 @@ syn keyword hipFlags hipReadModeElementType
 syn keyword hipFlags hipSuccess 
 syn keyword hipFlags hipTextureType1D 
 
+syn keyword hipFlags hipHostMallocDefault
+syn keyword hipFlags hipHostMallocPortable
+syn keyword hipFlags hipHostMallocMapped
+syn keyword hipFlags hipHostMallocWriteCombined
+
+syn keyword hipFlags hipHostRegisterDefault
+syn keyword hipFlags hipHostRegisterPortable
+syn keyword hipFlags hipHostRegisterMapped
+syn keyword hipFlags hipHostRegisterIoMemory
+
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