Toggle hybrid GPU mode via supergfxctl (#4277)

* Toggle hybrid GPU mode via supergfxctl

Very useful for Asus G14 and other laptops with NVIDIA + AMD iGPU
combos.

* Use correct exit

* Simplify

* Wording

* Revise switching process

* Spacing

* These are sudo actions

* Make it exe

* No need for extensions

Matches existing style

* Relying on the new config should be enough since we are restarting anyway

* Prevent race condition

* Reminder to add to OPR

default/systemd/system-sleep/force-igpu

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# Use the Vfio to Integrated trick to turn off NVIDIA dgpu when in integrated mode
+# without needing to restart the computer. This is needed because computers like the Asus G14
+# will wake after suspend in Hybrid mode, even if the system was in Integrated mode before
+# suspending.
+
+if [[ $1 == "post" ]]; then
+  # small delay so the device is fully re-enumerated
+  sleep 4
+
+  # force-bind dGPU to vfio (fully detached from nvidia)
+  /usr/bin/supergfxctl -m Vfio
+  sleep 1
+
+  # then go back to Integrated, which powers it off again
+  /usr/bin/supergfxctl -m Integrated
+fi

default/systemd/system/supergfxd.service.d/delay-start.conf

@@ -0,0 +1,6 @@
+[Service]
+# Delay startup to avoid race condition with display manager initialization
+# when booting in Integrated mode. Without this delay, the system can freeze
+# on boot because supergfxd tries to disable the dGPU while the display
+# subsystem is still initializing.
+ExecStartPre=/bin/sleep 5