Revert "x86/cpu: Add a steppings field to struct x86_cpu_id"

This reverts commit 6f2f28e71e6af993761b7a70bd2402a8d2096acf.

This is commit e9d7144597b10ff13ff2264c059f7d4a7fbc89ac upstream. Reverting this
commit makes the following patches apply cleanly. This patch is then reapplied.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>