media: raspberrypi: VIDEO_RASPBERRYPI_PISP_BE should depend on ARCH_BCM2835

Currently, the Raspberry Pi PiSP Backend (BE) ISP is only present on the
Broadcom BCM2712-based Raspberry Pi 5. Hence add a dependency on
ARCH_BCM2835, to prevent asking the user about this driver when
configuring a kernel without Broadcom BCM2835 family support. The
dependency can be relaxed if/when the encoder appears on other SoC
families.

Fixes: 12187bd5d4f8 ("media: raspberrypi: Add support for PiSP BE")
Signed-off-by: Geert Uytterhoeven <[e-mail]>
Acked-by: FLorian Fainelli <[e-mail]>
Acked-by: Jacopo Mondi <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

drivers/media/platform/raspberrypi/pisp_be/Kconfig

···
 	tristate "Raspberry Pi PiSP Backend (BE) ISP driver"
 	depends on V4L_PLATFORM_DRIVERS
 	depends on VIDEO_DEV
+	depends on ARCH_BCM2835 || COMPILE_TEST
 	select VIDEO_V4L2_SUBDEV_API
 	select MEDIA_CONTROLLER
 	select VIDEOBUF2_DMA_CONTIG