Kconfig: Disable -Wstringop-overflow for GCC globally

Kconfig: Disable -Wstringop-overflow for GCC globally

It turns out it was never just gcc-11 that was broken.  Apparently it
just happens to work on x86-64 with other gcc versions.

On arm64, I see warnings with gcc version 13.2.1, and the kernel test
robot reports the same problem on s390 with gcc 13.2.0.

Admittedly it seems to be just the new Xe drm driver, but this is
keeping me from doing my normal arm64 build testing.  So it gets
reverted until somebody figures out what causes the problem (and why it
doesn't show on x86-64, which is what makes me suspect it was never just
about gcc-11, and more about just random happenstance).

This also changes the Kconfig naming a bit - just make the "disable this
for GCC" conditional be one simple Kconfig entry, and we can put the gcc
version dependencies in that entry once we figure out what the correct
rules are.

The version dependency _may_ still end up being "gcc version larger than
11" if the issue is purely in the Xe driver, but even if that ends up
the case, let's make that all part of the "GCC_NO_STRINGOP_OVERFLOW"
logic.

For now, we just disable it for all gcc versions while the exact cause
is unknown.

Link: https://lore.kernel.org/all/202401161031.hjGJHMiJ-lkp@intel.com/T/
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>