buildmgr: Patch CLANG.cmake to be compatible with LLVM 19

In LLVM 19 the order of the target triple got swapped. I.e., none-unknown-eabi is not accepted anymore instead unknown-none-eabi is required. By dropping the unknown entirely the reduced target triple is accepted by all major versions 17, 18, and 19 by defaulting to vendor unknown.

Author: JonatanAntoni

tools/buildmgr/cbuildgen/config/CLANG.17.0.1.cmake

@@ -342,9 +342,9 @@ if(CLANG_ARCH STREQUAL "armv8")
   set(CLANG_CPU "-mcpu=${CLANG_MCPU}")
 else()
   if(CLANG_MFLOATABI STREQUAL "hard")
-    set(CLANG_TARGET "${CLANG_ARCH}-none-unknown-eabihf")
+    set(CLANG_TARGET "${CLANG_ARCH}-none-eabihf")
   else()
-    set(CLANG_TARGET "${CLANG_ARCH}-none-unknown-eabi")
+    set(CLANG_TARGET "${CLANG_ARCH}-none-eabi")
   endif()
   set(CLANG_CPU "--target=${CLANG_TARGET} -mcpu=${CLANG_MCPU} -mfloat-abi=${CLANG_MFLOATABI}")
 endif()