toolchain: drop old BR2_TOOLCHAIN_HAS_BINUTILS_BUG_* options
The BR2_TOOLCHAIN_HAS_BINUTILS_BUG_19615 and
BR2_TOOLCHAIN_HAS_BINUTILS_BUG_20006 options were last selected by the
BR2_TOOLCHAIN_EXTERNAL_CODESOURCERY_AMD64 toolchain, but this
toolchain has been removed as part of commit
d87e114a8ffacdc71f853e7c4ea76fd3c6958d22 in August 2020.
It's time to get rid of those two options that are never enabled.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>