[+] Kernel: Add SPI-gpio sharing to ssd1307 and ct1628.

- Was used mutex mechanism to share SPI bus.
- Add "GPIOlock" to platform device data.
  When two ore more drivers share one GPIO-spi software bus, we have to choose
  which one will requesting and register GPIO from kernel.
  Other driver wouldn't make request.
  Only one driver can lock GPIO (GPIOlock = 1). Other must have GPIOlock = 0.
- Preserv FB1 to ssd1307. Used fake FB register.
- Add gpio(11, 5) control. This PIO controls 12V power for OLED display (0/1 - off/on state)
- Make ssd1307 and ct1628 be kernel drivers.

Signed-off-by: Anton Proshutya <Anton.Proshutya@elecard.ru>
[+] Kernel: FB2 node reserved for ssd1307.

- FB2 node reserved for ssd1307;
- Add clearing GDDRAM in function 'ssd1307_controller_init' to avoid "trash"on display when STB booting.

Signed-off-by: Anton Proshutya <Anton.Proshutya@elecard.ru>