Add power supply derating factor to meson options

Add the option to specify the power supply derating factor.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Change-Id: Ibfbb52f64c5b9133fbbc8cbb267aa9618c079cc6
diff --git a/meson_options.txt b/meson_options.txt
index a948e46..7aad4ba 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -34,6 +34,14 @@
 )
 
 option(
+    'ps-derating-factor',
+    type : 'integer',
+    min:0, max:100,
+    description : 'Power supply derating factor',
+    value: 90
+)
+
+option(
     'with-host-communication-protocol',
     type : 'string',
     description : 'To specify the host communication protocol'