x86-power-control: add passthrough option

Add a power and reset button passthrough option
for emulating button behavior by directly controlling
the control output pin.

Change-Id: I50df3e604401b4afd43fa89a0709466bbf01638b
Signed-off-by: Renze Nicolai <renze@rnplus.nl>
diff --git a/meson.options b/meson.options
index c32fd30..07adb15 100644
--- a/meson.options
+++ b/meson.options
@@ -6,3 +6,5 @@
        description: 'Use hardware Reset Reason to control Power Restore. Note: this only works with Intel-BMC')
 option('ignore-soft-resets-during-post', type: 'feature', value : 'disabled',
        description: 'Ignore soft resets from host during POST')
+option('button-passthrough', type: 'feature', value : 'disabled',
+       description: 'Directly couple through power and reset buttons')