Set -m64 flag only on x86-64 hosts

-m64 only applies to x86-64, it's more reasonable to enable it only on x86_64 host.
It fixes build on some other platforms as well.

Provided by user r-value on github

https: //github.com/RadeonOpenCompute/rocminfo/pull/63
Change-Id: I9c1c40d3fa39b0a61d28041fe4998b5e1ad0cdcd

CMakeLists.txt

@@ -137,13 +137,12 @@ set(ROCMINFO_CXX_FLAGS ${ROCMINFO_CXX_FLAGS} -fmerge-all-constants)
 set(ROCMINFO_CXX_FLAGS ${ROCMINFO_CXX_FLAGS} -fms-extensions)
 set(ROCMINFO_CXX_FLAGS ${ROCMINFO_CXX_FLAGS} -Werror)
 set(ROCMINFO_CXX_FLAGS ${ROCMINFO_CXX_FLAGS} -Wall)
-set(ROCMINFO_CXX_FLAGS ${ROCMINFO_CXX_FLAGS} -m64)
 
 #
 # Extend the compiler flags for 64-bit builds
 #
 if((${CMAKE_HOST_SYSTEM_PROCESSOR} STREQUAL "x86_64") OR (${CMAKE_HOST_SYSTEM_PROCESSOR} STREQUAL "AMD64"))
-  set(ROCMINFO_CXX_FLAGS ${ROCMINFO_CXX_FLAGS} -msse -msse2)
+  set(ROCMINFO_CXX_FLAGS ${ROCMINFO_CXX_FLAGS} -m64 -msse -msse2)
 endif()
 
 #