[i2c] initial platform definitions for i2c support
[i2c] kconfig for I2C ability
[i2c] boilerplate for drivers i2c support
[i2c] stub implementation for i2c on ti arm mcus
[i2c] hookup lm4f120xl to the ti arm mcu i2c API. once the API is finalized,
    other TI MCUs will be supported too
[i2c] allow reference to I2C resources in board parameters
[ssd1306 lcd] stub implementation of ssd1306 lcd
[ssd1306 lcd] add ssd1306 to board params
[ssd1306 lcd] add ssd1306 to graphics test
[ssd1306] ssd1306 over i2c, not spi
[ssd1306 lcd] provide i2c address as ssd1306 param
[i2c] extern definition placeholder for ti arm mcu i2c resources
[i2c] lm4f120xl i2c0 definitions
[i2c] WRONG implementation of I2C in TI ARM MCUs, a placeholder for now