gpiolib: let gpiochip_add_pin_range() specify offset

Like with commit 3c739ad0df5eb41cd7adad879eda6aa09879eb76
it is not always enough to specify all the pins of a gpio_chip
from offset zero to be added to a pin map range, since the
mapping from GPIO to pin controller may not be linear at all,
but need to be broken into a few consecutive sub-ranges or
1-pin entries for complicated cases. The ranges may also be
sparse.

This alters the signature of the function to accept offsets
into both the GPIO-chip local pinspace and the pin controller
local pinspace.

Reviewed-by: Stephen Warren <[email protected]>
Reviewed-by: Viresh Kumar <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>
4 files changed