APUv2/v3 board support V2

From: Enrico Weigelt, metux IT consult
Date: Wed Feb 13 2019 - 15:57:49 EST

Hi folks,

this is version 2 of my APUv2/APUv3 series. Heavily reworked,
hope I've now addressed all issues of the last one.

Major changes are:
* using gpiod_lookup_table instead of hardcoded gpio numbers
* moved the PCHs gpio register definitions to the gpio drivers'
header (but keeping the actual assignments in the board driver,
as they're board speficic)
* moved IO resource definition from board to gpio driver
(the FCHs mmio base address could be changed, but nobody
seems to ever do it)
* added gpio line names
* moved the gpio driver's pdata definitions to::
* reduced some code redundancies and various cleanups

Possibly debatable:
* does is the assigned key code fit well ? (KEY_SETUP seemed the
best candidate to me, but I'm open to suggestions)
* should the pch gpio become a sub-device of some toplevel PCH
device ? (which then could also maintain the base address, etc)

Note: the keyboard device needs separate patch for gpiod_lookup_table
support in gpio-keys-polled driver. I'll sent it separately.


Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
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