linux (Generic): update to linux-4.17.6

[MilhouseVH]

https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.17.3
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.17.4
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.17.5
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.17.6

[MilhouseVH]

Intel ucode - only Xeon CPUs so not particularly relevant but keeps us up-to-date:

== 20180703 Release ==
-- Updates upon 20180425 release --
Processor             Identifier     Version       Products
Model        Stepping F-MO-S/PI      Old->New
---- updated platforms ------------------------------------
SNB-EP       C1       6-2d-6/6d 0000061c->0000061d Xeon E5
SNB-EP       C2       6-2d-7/6d 00000713->00000714 Xeon E5
IVT          C0       6-3e-4/ed 0000042c->0000042d Xeon E5 v2; Core i7-4960X/4930K/4820K
IVT          D1       6-3e-7/ed 00000713->00000714 Xeon E5 v2
HSX-E/EP/4S  C0       6-3f-2/6f 0000003c->0000003d Xeon E5 v3
HSX-EX       E0       6-3f-4/80 00000011->00000012 Xeon E7 v3
SKX-SP/D/W/X H0       6-55-4/b7 02000043->0200004d Xeon Bronze 31xx, Silver 41xx, Gold 51xx/61xx Platinum 81xx, D/W-21xx; Core i9-7xxxX
BDX-DE       A1       6-56-5/10 0e000009->0e00000a Xeon D-15x3N