ARM: k2g: Add pinmux support for K2G ICE evm

ARM: k2g: Add pinmux support for K2G ICE evm

Add basic pinmux data for new K2G ICE evm. Also add pinmuxing for a
generic K2G evm which includes I2C 0 and 1 used for board detection
purposes.

Since multiple K2G boards are supported that means initially generic
pinmuxing should be used when board detection hasn't ran. Once board
detection runs the proper pinmuxing can be reran to match the board
being ran on.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>