hardware: correctly detect early 2015 MacBook Pro.

Closes Homebrew/homebrew#38996.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Library/Homebrew/os/mac/hardware.rb

@@ -44,6 +44,8 @@ module MacCPUs
         :ivybridge
       when 0x10B282DC # Haswell
         :haswell
+      when 0x582ed09c # Broadwell
+        :broadwell
       else
         :dunno
       end

Library/Homebrew/test/test_hardware.rb

@@ -7,7 +7,7 @@ class HardwareTests < Homebrew::TestCase
   end
 
   def test_hardware_intel_family
-    families = [:core, :core2, :penryn, :nehalem, :arrandale, :sandybridge, :ivybridge, :haswell]
+    families = [:core, :core2, :penryn, :nehalem, :arrandale, :sandybridge, :ivybridge, :haswell, :broadwell]
     assert_includes families, Hardware::CPU.family
   end if Hardware::CPU.intel?
 end