ARM: dts: Add dts files for sam9x60ek

ARM: dts: Add dts files for sam9x60ek

add device tree files for sam9x60ek board with below changes.

- Add initial device nodes (pmc, pinctrl, sdhc, dbgu & pit)
- Add the reg property for the pinctrl node.
- Add the "u-boot,dm-pre-reloc" property to determine which nodes
  are used by the board_init_f stage.

Signed-off-by: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>
[prasanthi.chellakumar@microchip.com: fix style/whitespace issues]
Signed-off-by: Prasanthi Chellakumar <prasanthi.chellakumar@microchip.com>
[nicolas.ferre@microchip.com:
- fix gclk,
- fix pio/pinctrl controller definition and allow to have more
  than only PIOA for this SoC,
- removing pinctrl address]
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[claudiu.beznea@microchip.com:
- use SAM9X60's compatible for pinctrl
- add drive strength and slew rate options for SDMMC0 pins.]
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
[tudor.ambarus@microchip.com:
- u-boot,dm-pre-reloc property in dedicated file,
- fix pit len, starts from 0xFFFFFE40 and it is of len 0x10]
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>