clkdev: Remove __init marking from clkdev_add_table()

To support registration of clock tables from drivers that
initialize after the kernel has booted, remove the __init
marking.

Change-Id: I264395652772b30960c0168121194870b541e18f
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
(cherry picked from commit ba60861f28c4039f381b8ed3a5f48a0df045be67)
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>