tools_def: Remove unneeded -Wno-unneeded-internal-declaration for CLA…

…NGDWARF

This is already worked around by the alternative version
of MDEPKG_NDEBUG DEBUG() for __clang__ which is provided
in MdePkg DebugLib.h, therefore the reason why this flag
was added in EDK-II no longer applies.

BaseTools/Conf/tools_def.template

@@ -1147,7 +1147,7 @@ DEFINE CLANGDWARF_IA32_X64_ASLDLINK_FLAGS = DEF(CLANGDWARF_IA32_X64_DLINK_COMMON
 DEFINE CLANGDWARF_IA32_X64_DLINK_FLAGS    = DEF(CLANGDWARF_IA32_X64_DLINK_COMMON) -Wl,--entry,$(IMAGE_ENTRY_POINT) -u $(IMAGE_ENTRY_POINT) -Wl,-Map,$(DEST_DIR_DEBUG)/$(BASE_NAME).map,--whole-archive
 DEFINE CLANGDWARF_IA32_DLINK2_FLAGS       = -no-pie
 
-DEFINE CLANGDWARF_WARNING_OVERRIDES = -Wno-parentheses-equality -Wno-tautological-compare -Wno-tautological-constant-out-of-range-compare -Wno-empty-body -Wno-unused-const-variable -Wno-varargs -Wno-unknown-warning-option -Wno-unused-but-set-variable -Wno-unused-const-variable -Wno-unaligned-access -Wno-unneeded-internal-declaration
+DEFINE CLANGDWARF_WARNING_OVERRIDES = -Wno-parentheses-equality -Wno-tautological-compare -Wno-tautological-constant-out-of-range-compare -Wno-empty-body -Wno-unused-const-variable -Wno-varargs -Wno-unknown-warning-option -Wno-unused-but-set-variable -Wno-unused-const-variable -Wno-unaligned-access
 DEFINE CLANGDWARF_ALL_CC_FLAGS      = DEF(GCC5_ALL_CC_FLAGS) DEF(CLANGDWARF_WARNING_OVERRIDES) -fno-stack-protector -mms-bitfields -Wno-address -Wno-shift-negative-value -Wno-unknown-pragmas -Wno-incompatible-library-redeclaration -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -msoft-float -mno-implicit-float  -ftrap-function=undefined_behavior_has_been_optimized_away_by_clang -funsigned-char -fno-ms-extensions -Wno-null-dereference
 
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