You can install virtually the same set of software in AWS EC2 as that of your laptop. At least, this is the case for me with Ubuntu 16.04 LTS, in which sfcgal works out of the box with
You can also install sfcgal by compiling it from source.
-- Update --
As pointed out in the comments by @vince, if you are using RDS, it does not provide access to the host OS on which the PG service is running. Compiling new binaries is not an option.
From the RDS FAQ, you can send request to AWS for installing additional extensions:
Q: What are the extensions supported by RDS for PostgreSQL?
You can check the list of supported extensions in the Amazon RDS User
Guide. To request support for additional extensions, you can send an
email to firstname.lastname@example.org with the extension
name and use case.