mfd: tps65910: Make it explicitly non-modular

The Kconfig currently controlling compilation of this code is:

drivers/mfd/Kconfig:config MFD_TPS65910
drivers/mfd/Kconfig-    bool "TI TPS65910 Power Management chip"

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

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 was not in use by this code, the init ordering
remains unchanged with this commit.

We don't replace module.h with init.h since the file already has that.
We do delete an unused moduleparam.h include though.

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
was (or is now) contained at the top of the file in the comments.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>