package/timescaledb: new package

TimescaleDB is an open-source database designed to make SQL scalable
for time-series data.  It is engineered up from PostgreSQL and
packaged as a PostgreSQL extension, providing automatic partitioning
across time and space (partitioning key), as well as full SQL support.

Signed-off-by: Maxim Kochetkov <fido_max@inbox.ru>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>