remoteproc: qcom q6v5: fix modular build

The new driver only works as built-in code at the moment but fails
with a link error when configured as a loadable module:

WARNING: modpost: missing MODULE_LICENSE() in drivers/remoteproc/qcom_q6v5.o
see include/linux/module.h for more information
ERROR: "qcom_q6v5_init" [drivers/remoteproc/qcom_q6v5_pil.ko] undefined!
ERROR: "qcom_q6v5_wait_for_start" [drivers/remoteproc/qcom_q6v5_pil.ko] undefined!
ERROR: "qcom_q6v5_prepare" [drivers/remoteproc/qcom_q6v5_pil.ko] undefined!
ERROR: "qcom_q6v5_unprepare" [drivers/remoteproc/qcom_q6v5_pil.ko] undefined!
ERROR: "qcom_q6v5_request_stop" [drivers/remoteproc/qcom_q6v5_pil.ko] undefined!
ERROR: "qcom_q6v5_init" [drivers/remoteproc/qcom_adsp_pil.ko] undefined!
ERROR: "qcom_q6v5_wait_for_start" [drivers/remoteproc/qcom_adsp_pil.ko] undefined!
ERROR: "qcom_q6v5_prepare" [drivers/remoteproc/qcom_adsp_pil.ko] undefined!
ERROR: "qcom_q6v5_unprepare" [drivers/remoteproc/qcom_adsp_pil.ko] undefined!
ERROR: "qcom_q6v5_request_stop" [drivers/remoteproc/qcom_adsp_pil.ko] undefined!

This exports the internal symbols as needed and adds the MODULE_LICENSE()
and MODULE_DESCRIPTION() tags. I could not figure out the author, so I
did not add a MODULE_AUTHOR() tag for now.

Fixes: 3b415c8f ("remoteproc: q6v5: Extract common resource handling")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>