Remove mv_config.pyl entry for Nexus 5 & 6
Remove mv_config.pyl entry for Nexus 5 & 6

They are added back under the FYI waterfall in https://codereview.chromium.org/1972513002/

BUG=490984, 607730, 607731

Review-Url: https://codereview.chromium.org/1959883002
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#393705}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk