memory: atmel-ebi: make it explicitly non-modular

The Kconfig currently controlling compilation of this code is:

drivers/memory/Kconfig:config ATMEL_EBI
drivers/memory/Kconfig: bool "Atmel EBI driver"

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

Lets remove the few remaining modular references, 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.

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.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>