[arm] Eliminate SUBTARGET_CPU_DEFAULT

[arm] Eliminate SUBTARGET_CPU_DEFAULT

	* config.gcc (arm-wrs-vxworks): Set target_cpu_cname.
	(arm*-freebsd*): Likewise.
	(arm*-*-netbsdelf*): Likewise.
	(arm*-*-linux*): Likewise.
	(arm*-*-uclinux*eabi*): Likewise.
	(arm*-*-phoenix*): Likewise.
	(arm*-*-eabi*, arm*-*-symbianelf*, arm*-*-rtems*): Likewise.
	(arm*-*-*): Don't clobber target_cpu_cname when --with-cpu is not
	specified.  Default to arm6 if target_cpu_cname is not set.
	* arm/arm.c (arm_option_override): Simplify logic.  Assert that the
	default cpu has been correctly configured.
	* arm/arm.h (TARGET_CPU_DEFAULT): Delete.
	(target_cpus): Delete TARGET_CPU_generic, add TARGET_CPU_num_cores.
	* arm/freebsd.h (SUBTARGET_CPU_DEFAULT): Delete.
	* arm/linux-eabi.h (SUBTARGET_CPU_DEFAULT): Delete.
	* arm/linux-elf.h (SUBTARGET_CPU_DEFAULT): Delete.
	* arm/symbian.h (SUBTARGET_CPU_DEFAULT): Delete.
	* arm/unknown-elf.h (SUBTARGET_CPU_DEFAULT): Delete.

From-SVN: r241827