Update silk board support

Summary of changes:
* i2c: Support ACK by HW auto restart after NACK
	Even if R-Car I2C received NACK, after that it might receive ACK
	by HW auto restart. In case of that, driver would continue
	process.
	If R-Car I2C didn't receive ACK, the driver would detect
	timeout and would report NACK as -ENXIO.
* sdhi1: Fix SDHI1 write protect pin detection
* ethernet: Ethernet phy interrupt is connected to IRQ8