Can I revert to my previous version app in iTunes Connect?

I have app in App Store, I submitted version 1.1, after Apple reviewed, approved and published it, I noticed there is a clear major bug, so I had to suspend my app from App Store.

I submitted a new version 1.2, you know it would take 5-7 days to be reviewed and published, can I revert to my previous version app (1.0) while the new version is released?

Actually there is just one way :

Set the availability date for buggy version to far future, then submit new version and ask for a expedited review. After these you should have new version reviewed under 48 hours, depending on weekday.

Open the app in iTunes Connect and click "Rights and Pricing" top right. You get a message like this: "You have selected an Available Date in the future. This will remove your currently live version from the App Store until the new date. Changing Available Date affects all versions of the application, both Ready For Sale and In Review."

Also you can request a faster review for your next update: https://developer.apple.com/appstore/contact/?topic=expedite

No sadly you cannot according to Apple, here's an excerpt from the iTunes Connect FAQ :

Question: The new version of my app on the App Store has a bug. Can I use a previous version to replace it?

No. You cannot revert to a previous version on the App Store. You must submit a new version.

Source : iTunes Connect FAQ

So, It is quite clear that we can't revert to the previous version on the App Store and the only solution is to submit a new version to the store. But We can fasten up the reviewing process by requesting the Expedited reviews. please go to the link(Expedited Review Form) and Fill up the form.