mb/purism: remove duplicate ACPI power button

These platforms use the standard fixed function power button
and do not need a second power button device declared or the
kernel will end up with two devices reporting the same event.

Same change was applied to all google mainboards in
CB:27272 which contains more detail.

Change-Id: I17c85e43493530d04f4fa13f33bec6d027cb3147
Signed-off-by: Matt DeVillier <matt.devillier@puri.sm>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39577
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/purism/librem_bdw/acpi/mainboard.asl

@@ -30,18 +30,6 @@ Scope (\_SB)
 		}
 	}
 
-	Device (PWRB)
-	{
-		Name (_HID, EisaId ("PNP0C0C"))
-
-		Method (_STA)
-		{
-			Return (0xF)
-		}
-
-		Name (_PRW, Package () { 27, 4 })
-	}
-
 	Device (SLPB)
 	{
 		Name (_HID, EisaId ("PNP0C0E"))

src/mainboard/purism/librem_skl/acpi/mainboard.asl

@@ -30,18 +30,6 @@ Scope (\_SB)
 		}
 	}
 
-	Device (PWRB)
-	{
-		Name (_HID, EisaId ("PNP0C0C"))
-
-		Method (_STA)
-		{
-			Return (0xF)
-		}
-
-		Name (_PRW, Package () { 27, 4 })
-	}
-
 	Device (SLPB)
 	{
 		Name (_HID, EisaId ("PNP0C0E"))