media: staging: media: atomisp: add PMIC_OPREGION dependency

Without that driver, there is a link failure in

ERROR: modpost: "intel_soc_pmic_exec_mipi_pmic_seq_element"
[drivers/staging/media/atomisp/pci/atomisp_gmin_platform.ko] undefined!

Add an explicit Kconfig dependency.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>