Tweaks for Turris 1.x router
I rebased support patch once again from kernel 4.14 (HBK/HBL) branch and I noticed that we forgot to include in kernel 5.4 configs like CONFIG_HIGHMEM and CONFIG_CRYPTO_XZ (not sure about this one)
Added 2 (!) patches which we were using on kernel 4.14 and I moved them to 5.4 folder. Not sure, if we need them.
I did this because Turris OS 6.0 does not run on Turris 1.x routers, but for now, I didn't do compile and run test. I will do it later.