Remove row control for topSites on new tab page

[cezaraugusto]

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Ran git rebase -i to squash commits (if needed).

Test Plan:

fix #5482

Auditors: @bbondy

Test Plan:

• there should be no row control for topSites

[bbondy]

I was thinking we would just set display: none for now but it's ok since we can always get the code back. Merging.