docs: replace autotools intructions with meson equivalent

Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>

docs/submittingpatches.html

@@ -141,7 +141,7 @@ do whatever testing is prudent.
 
 <p>
 You should always run the Mesa test suite before submitting patches.
-The test suite can be run using the 'make check' command. All tests
+The test suite can be run using the 'meson test' command. All tests
 must pass before patches will be accepted, this may mean you have
 to update the tests themselves.
 </p>
@@ -160,10 +160,10 @@ to run your tests on each commit. Assuming your branch is based off
 <code>origin/master</code>, you can run:
 </p>
 <pre>
-$ git rebase --interactive --exec "make check" origin/master
+$ git rebase --interactive --exec "meson test -C build/" origin/master
 </pre>
 <p>
-replacing <code>"make check"</code> with whatever other test you want to
+replacing <code>"meson test"</code> with whatever other test you want to
 run.
 </p>
 
@@ -466,7 +466,7 @@ within the commit summary.
 </pre>
 <li>Test for build breakage between patches e.g last 8 commits.
 <pre>
-    git rebase -i --exec="make -j4" HEAD~8
+    git rebase -i --exec="ninja -C build/" HEAD~8
 </pre>
 <li>Sets the default mailing address for your repo.
 <pre>