OWNERS: add Patrick Williams

Based on the github stats[1], I seem to have significantly more LOC
contribution to this repo than everyone else and 3rd in commits.

1. https://github.com/openbmc/openbmc-build-scripts/graphs/contributors

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ie006aca7520cf903d4e3741b8bdfc71c847c47b4
diff --git a/MAINTAINERS b/MAINTAINERS
index 5e0e2e5..f535173 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -44,5 +44,6 @@
 
 M:  Andrew Geissler <geissonator@yahoo.com> <geissonator!>
 M:  Joel Stanley <joel@jms.id.au> <shenki!>
+M:  Patrick Williams <patrick@stwcx.xyz> <stwcx!>
 R:  Matthew Barth <msbarth@linux.ibm.com> <msbarth!>
 R:  Andrew Jeffery <andrew@aj.id.au> <amboar!>