ARM: configs: multi_v5_defconfig: re-enable CONFIG_V4L_PLATFORM_DRIVERS

ARM: configs: multi_v5_defconfig: re-enable CONFIG_V4L_PLATFORM_DRIVERS

Commit 06b93644f4d1 ("media: Kconfig: add an option to filter in/out
platform drivers") introduced CONFIG_MEDIA_PLATFORM_SUPPORT, to allow
more fine grained control over the inclusion of certain Kconfig files.
multi_v5_defconfig was selecting some drivers described in
drivers/media/platform/Kconfig, which now wasn't included anymore.

Explicitly set the new symbol in multi_v5_defconfig to bring those
drivers back.
This enables some new V4L2 and VIDEOBUF2 features, but as modules only.

Fixes: 06b93644f4d1 ("media: Kconfig: add an option to filter in/out platform drivers")
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Link: https://lore.kernel.org/r/20220317183043.948432-3-andre.przywara@arm.com'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>