fix case in compiler name check

Co-authored-by: xoviat <[email protected]>

Author: martin-frbg

cmake/system.cmake

@@ -155,7 +155,7 @@ if (DEFINED TARGET)
         else()
           set (KERNEL_DEFINITIONS "${KERNEL_DEFINITIONS} -march=skylake-avx512")
         endif()
-    elseif (${CMAKE_C_COMPILER_ID} STREQUAL "CLANG" OR ${CMAKE_C_COMPILER_ID} STREQUAL "AppleClang")
+    elseif (${CMAKE_C_COMPILER_ID} STREQUAL "Clang" OR ${CMAKE_C_COMPILER_ID} STREQUAL "AppleClang")
          if (${CMAKE_C_COMPILER_VERSION} VERSION_GREATER 8.99)
           set (KERNEL_DEFINITIONS "${KERNEL_DEFINITIONS} -march=cooperlake")
         else()