kernel: update patchset

cherry-pick the following commits:

5b6dea157d1a07d842bd20b41511f980e89c7a57
Update bcm2708.c to use CONFIG_BCM2708_SPIDEV rather than CONFIG_SPI

3807768e1255b61b3dff8566c22fef9ef9a61349
Only init gpio pins of selected i2c bus

a0d6e08e95b4cb6b4ee4beb8deb8280810f37592
Avoid responding to unexpected I2C interrupts