mtd: maps: make uclinux.c driver more explicitly non-modular

The Kconfig for this support is currently declared with:

config MTD_UCLINUX
        bool "Generic uClinux RAM/ROM filesystem support"

...meaning that it currently is not being built as a module by anyone.
Lets remove as much of the modular evidence that we can, so that when
reading the driver there is less 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.

We also replace module.h with moduleparam.h since the file does use
a module_param,  and leaving it as such is currently the easiest way
to remain compatible with existing boot arg use cases.

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: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>