Update intel-microcode-netbsd to 20200616.

== 20200616 Release ==
-- Updates upon 20200609 release --
Processor            Identifier    Version      Products
Model        Stepping F-MO-S/PI      Old->New
---- new platforms ----------------------------------------

---- updated platforms ------------------------------------
SKL-U/Y      D0      6-4e-3/c0 000000dc->000000d6 Core Gen6 Mobile
SKL-U23e    K1      6-4e-3/c0 000000dc->000000d6 Core Gen6 Mobile
SKL-H/S      R0/N0    6-5e-3/36 000000dc->000000d6 Core Gen6; Xeon E3 v5

---- removed platforms ------------------------------------

(msaitoh)