Log Message:
Update intel-microcode-netbsd to 20200520.

== 20200520 Release ==
-- Updates upon 20200508 release --
Processor             Identifier     Version       Products
Model        Stepping F-MO-S/PI      Old->New
---- new platforms ----------------------------------------

---- updated platforms ------------------------------------
SNB-E/EN/EP  C1/M0    6-2d-6/6d 0000061f->00000621 Xeon E3/E5, Core X
SNB-E/EN/EP  C2/M1    6-2d-7/6d 00000718->0000071a Xeon E3/E5, Core X

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