reverts skylake updates which broke boot on some but not all systems
https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/issues/31
breakage reported by Abel Abraham Camarillo Ojeda on i3-6100U 06-4e-03
not seen by sthen@ on i5-6200U 06-4e-03
ok sthen@
== 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 ------------------------------------
f3d747a21a