soc: qcom/llcc: add MODULE_LICENSE tag

The lack of a MODULE_LICENSE tag prevents building the llcc driver
as a loadable module:

FATAL: modpost: GPL-incompatible module llcc-slice.ko uses GPL-only symbol 'ktime_get'

This adds the appropriate license and description tags.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Gross <andy.gross@linaro.org>