Revert "tests/periph/timer: increase test timeout"

This reverts commit 9e7e8a9.

tests/periph/timer/tests/01-run.py

@@ -9,16 +9,13 @@
 import sys
 from testrunner import run
 
-# The test can take some time when timers are slow ticking
-TIMEOUT = 90
-
 
 def testfunc(child):
     # Make sure the expected application is actually flashed
     child.expect('Test for peripheral TIMERs')
     # The C application carefully evaluates the test results, no need to
     # re-implement that wheel in python and just check for the test to succeed
-    child.expect('TEST SUCCEEDED', timeout=TIMEOUT)
+    child.expect('TEST SUCCEEDED')
 
 
 if __name__ == "__main__":