ec/google/chromec: Update ACPI handlers for GPU

There is a new field in EC EMEM for arbitrary GPU data to be passed
from EC to ACPI FW; this patch adds support for it.

Also the current host event for _Q0C (EC_HOST_EVENT_USB_CHARGER) is
unused, and is being repurposed in the next CL, so this patch drops
the handler.

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: Iff6f935a5bdc8c47277eaa6bcbedd5fc5ed311a4
Reviewed-on: https://review.coreboot.org/c/coreboot/+/65485
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Ivy Jian <ivy.jian@quanta.corp-partner.google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/ec/google/chromeec/acpi/ec.asl

@@ -169,7 +169,6 @@ Device (EC0)
 			\_SB.DPTC()
 		}
 #endif
-
 	}
 
 	/* Read requested temperature and check against EC error values */
@@ -301,12 +300,6 @@ Device (EC0)
 		Notify (\_TZ, 0x80)
 	}
 
-	// USB Charger
-	Method (_Q0C, 0, NotSerialized)
-	{
-		Printf ("EC: USB CHARGER")
-	}
-
 	// Key Pressed
 	Method (_Q0D, 0, NotSerialized)
 	{

src/ec/google/chromeec/acpi/emem.asl

@@ -47,3 +47,5 @@ BSER, 64,	// Battery Serial String
 BTYP, 64,	// Battery Type String
 Offset (0x80),
 ALS0, 16,	// ALS reading 0 in lux
+Offset (0xa6),
+GPUD, 8,	// GPU Data