cpu.rb: add skylake to Linuxbrew
cpu.rb: add skylake to Linuxbrew

Closes Linuxbrew/brew#293

Signed-off-by: Maxim Belkin <032baa6ccf1d4eaa4536fc4f9b83b9a1f593449a@gmail.com>
rwhogg/brew,rwhogg/brew,Linuxbrew/brew,rwhogg/brew,Linuxbrew/brew,maxim-belkin/brew,maxim-belkin/brew,Linuxbrew/brew,maxim-belkin/brew,hanxue/linuxbrew,Linuxbrew/brew,hanxue/linuxbrew,hanxue/linuxbrew