Change in coreboot[master]: soc/intel/skylake: change GPI RXEVCFG default to edge

[Kane Chen (Code Review)]

Kane Chen has posted comments on this change. ( https://review.coreboot.org/19992 )

Change subject: soc/intel/skylake: change GPI RXEVCFG default to edge
......................................................................

Patch Set 2:
> (1 comment)

Hi Aaron, 
The issue happens in below scenario.
The SD_CD is edge trigger.

BIOS sets GPI for SD_CD in gpio.h and claims GpioInt in asl code.
When BIOS hands over to OS, the gpio interrupt is not enabled yet.
But with original macro, it leaves all GPI to Level trigger.(GPI_IE is not yet set here)
Once OS takes control and init GpioInt for SD_CD, then issue happens in a very small window (it's still level trigger)
After OS correctly config the interrupt to EDGE from level, then the unused interrupts stop immediately.

Thanks.