gitignore: Update with some filetypes

Update .gitignore to ignore .swp and .patch files.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <79262dbe1f7888eb02e1911501eebafa6f2f6400.1616583806.git.viresh.kumar@linaro.org>
Message-Id: <20210720232703.10650-2-alex.bennee@linaro.org>

.gitignore

@@ -13,3 +13,5 @@ GTAGS
 *~
 *.ast_raw
 *.depend_raw
+*.swp
+*.patch