media: Kconfig: move comment to siano include

Showing this comment without showing the Siano mmc option
is very weird! Place the option together, and make it
visible only when showing Siano configuration.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/mmc/Kconfig

 # SPDX-License-Identifier: GPL-2.0-only
-comment "Supported MMC/SDIO adapters"
 source "drivers/media/mmc/siano/Kconfig"

drivers/media/mmc/siano/Kconfig

@@ -2,6 +2,8 @@
 #
 # Siano Mobile Silicon Digital TV device configuration
 #
+comment "MMC/SDIO DVB adapters"
+	depends on DVB_CORE && HAS_DMA && MMC
 
 config SMS_SDIO_DRV
 	tristate "Siano SMS1xxx based MDTV via SDIO interface"