clk: meson8b: make it explicitly non-modular

The Kconfig currently controlling compilation of this code is:

drivers/clk/meson/Kconfig:config COMMON_CLK_MESON8B
drivers/clk/meson/Kconfig:      bool

...meaning that it currently is not being built as a module by anyone.
However a recent commit added a bunch of modular boilerplate to this
driver.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Also note that MODULE DEVICE_TABLE/ALIAS are no-op when non-modular.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: linux-clk@vger.kernel.org
Cc: linux-amlogic@lists.infradead.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160704211220.5685-2-paul.gortmaker@windriver.com