lib/Kconfig.debug: disable CONFIG_DEBUG_INFO_BTF for Hexagon

pahole, which generates BTF, relies on elfutils to process DWARF debug
info.  Because kernel modules are relocatable files, elfutils needs to
resolve relocations when processing the DWARF .debug sections.

Hexagon is not supported in binutils or elfutils, so elfutils is unable to
process relocations in kernel modules, causing pahole to crash during BTF
generation.

Do not allow CONFIG_DEBUG_INFO_BTF to be selected for Hexagon until it is
supported in elfutils, so that there are no more cryptic build failures
during BTF generation.

Link: https://lkml.kernel.org/r/20240105-hexagon-disable-btf-v1-1-ddab073e7f74@kernel.orgSigned-off-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202312192107.wMIKiZWw-lkp@intel.com/Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Brian Cain <bcain@quicinc.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/Kconfig.debug

@@ -378,6 +378,8 @@ config DEBUG_INFO_BTF
 	depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
 	depends on BPF_SYSCALL
 	depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
+	# pahole uses elfutils, which does not have support for Hexagon relocations
+	depends on !HEXAGON
 	help
 	  Generate deduplicated BTF type information from DWARF debug info.
 	  Turning this on expects presence of pahole tool, which will convert