pinctrl: meson: make explicitly non-modular

The Kconfig currently controlling compilation of this code is:

drivers/pinctrl/Kconfig:config PINCTRL_MESON
drivers/pinctrl/Kconfig:        bool

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modularity so that when reading the
driver there is no doubt it is builtin-only.

Since module_platform_driver() uses the same init level priority as
builtin_platform_driver() the init ordering remains unchanged with
this commit.

We don't replace module.h with init.h since the file already has that.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

Cc: Beniamino Galvani <b.galvani@gmail.com>
Cc: Carlo Caione <carlo@endlessm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Antoine Tenart <antoine.tenart@free-electrons.com>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>