CI: remove unnecessary clang settings

With the resolution of meta-clang issue 766 and
OE-Core 15d09b02b2632ab1cabc3b1bd9f521e6d3d3b83f
many of the settings are no longer necessary to be set as part of our
CI.  Remove them, as it is causing other issues with CI.

Signed-off-by: Jon Mason <jon.mason@arm.com>

ci/clang.yml

@@ -10,12 +10,3 @@ repos:
 local_conf_header:
   toolchain: |
     TOOLCHAIN = "clang"
-    PREFERRED_PROVIDER_llvm = "clang"
-    PREFERRED_PROVIDER_llvm-native = "clang-native"
-    PREFERRED_PROVIDER_nativesdk-llvm = "nativesdk-clang"
-    PROVIDES:pn-clang = "llvm"
-    PROVIDES:pn-clang-native = "llvm-native"
-    PROVIDES:pn-nativesdk-clang = "nativesdk-llvm"
-    # This is needed to stop bitbake getting confused about what clang/llvm is
-    # being used, see https://github.com/kraj/meta-clang/pull/766
-    BBMASK += "/meta/recipes-devtools/llvm/llvm.*\.bb"