Implement get_multiple for ACCES and PC/104 drivers

Changes in v4:
- Remove STX104 patch as it has been picked up through the IIO tree
- Utilize GENMASK for 104-IDIO-16 patch to avoid long literal bitmasks
- Fix off-by-one errors for port_mask initializations
- Add end comma to ports arrays initializations for consistency

This patchset implements get_multiple callbacks for the PC104 GPIO drivers as well as the PCI-IDIO-16 and PCIe-IDIO-24 GPIO drivers. These devices all acquire the multiple input lines with a single read, so utilizing the get_multiple callback can provide improvement for those users who regularly access multiple input lines.

While developing this patchset I noticed many of these devices make use of Intel 8255 compatible interfaces for their I/O. I may write a generic 8255 GPIO driver in the future to reduce some of the redundant code I see pop among the drivers for these devices.

William Breathitt Gray (7):
gpio: 104-idio-16: Implement get_multiple callback
gpio: pci-idio-16: Implement get_multiple callback
gpio: pcie-idio-24: Implement get_multiple/set_multiple callbacks
gpio: 104-dio-48e: Implement get_multiple callback
gpio: 104-idi-48: Implement get_multiple callback
gpio: gpio-mm: Implement get_multiple callback
gpio: ws16c48: Implement get_multiple callback

 drivers/gpio/gpio-104-dio-48e.c  |  47 ++++++++++++++++
 drivers/gpio/gpio-104-idi-48.c   |  47 ++++++++++++++++
 drivers/gpio/gpio-104-idio-16.c  |  15 +++++
 drivers/gpio/gpio-gpio-mm.c      |  47 ++++++++++++++++
 drivers/gpio/gpio-pci-idio-16.c  |  50 +++++++++++++++++
 drivers/gpio/gpio-pcie-idio-24.c | 117 +++++++++++++++++++++++++++++++++++++++
 drivers/gpio/gpio-ws16c48.c      |  47 ++++++++++++++++
 7 files changed, 370 insertions(+)

2.16.2