toolchain/Config.in: extend gcc bug 43744 to every sh architecture

Gcc bug 43744 affects seems to affect all SH family because it already
affects:
1) sh4, here you can find a buildroot defconfig that fails to build:
http://autobuild.buildroot.net/results/1db/1db6c59c98e3c09fa13277076ee2fbe7967f1f6b/defconfig
2) sh4a, here you can find a buildroot defconfig that fails to build:
http://autobuild.buildroot.net/results/cf272cdc5be2faf4070de3d235ec7a0f7190867a/defconfig
Note also that gcc bugzilla entry reports the bug for SH and not for
sub-architectures:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=43744



So let's extend the bug to BR2_sh to match the entire SH architecture.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>