The recent kernel v6.6.31 update broke BTF-enabled builds since upstream
Linux added a prompt for config option DEBUG_INFO_BTF_MODULES in commit
2166cb2e21 ("bpf, kconfig: Fix DEBUG_INFO_BTF_MODULES Kconfig definition").
Fix by updating Config-kernel.in to add the option, cleaning up a related
dependency and whitespace also.
Fixes: 10d77b9bc3 ("kernel: bump 6.6 to 6.6.31")
Signed-off-by: Tony Ambardar <itugrok@yahoo.com>