custom/Cygwin-posix.cfg: Remove -USTRICT_ANSI, make-target-options.
custom/FreeBSD-posix.cfg: Remove make-target-options.
custom/HPUX9-posix.cfg: Dito.
custom/Linux-posix.cfg: Dito.
custom/Solaris-posix.cfg: Dito.
custom/arm_bare_bsp.cfg: Dito.
custom/armulator.cfg: Dito.
custom/erc32.cfg: Remove CONSOLE_USE_POLLED, CONSOLE_USE_INTERRUPTS.
custom/i386ex.cfg: Remove make-target-options.
custom/i960sim.cfg: Remove make-target-options.
custom/mvme2307.cfg: Remove CONSOLE_USE_POLLED, CONSOLE_USE_INTERRUPTS.
custom/rxgen960.cfg: Remove make-target-options, cleanup comments.
custom/score603e.cfg: Remove CONSOLE_USE_POLLED, CONSOLE_USE_INTERRUPTS.
custom/vegaplus.cfg: Remove make-target-options.