Allow patch files to have trailing spaces

A patch file generated by the "git diff" command may have lines
consisting of a single space character.

Change-Id: I4b7038bc795cf8e3581d472492d45bb578a01a19

.gitattributes

diff --git a/.gitattributes b/.gitattributes
index ffc6912..991963a 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -16,3 +16,4 @@
 *.pjt        -crlf
 *.vcp        -crlf
 *.inf        -crlf
+*.patch      -whitespace