drm/i915/selftests: Follow up on increase timeout in i915_gem_contexts selftests

drm/i915/selftests: Follow up on increase timeout in i915_gem_contexts selftests

Follow up on below commit, to increase the timeout further on new
platforms, to accomodate the additional time required for the completion
of guc submissions for numerous requests created in loop.

commit c12c92cf83f0a4211022a1467c67e3a42fd6d01e
Author: Matthew Brost <matthew.brost@intel.com>
Date:   Mon Jul 26 20:17:03 2021 -0700

    drm/i915/selftests: Increase timeout in i915_gem_contexts selftests

Signed-off-by: Bruce Chang <yu.bruce.chang@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211207003845.12419-1-yu.bruce.chang@intel.com