media: ipu-bridge: fix ipu6 Kconfig dependencies

Commit 4670c8c3 ("media: ipu-bridge: Fix Kconfig dependencies") changed
how IPU_BRIDGE dependencies are handled for all drivers, but the IPU6
variant was added the old way, which causes build time warnings when I2C is
turned off:

WARNING: unmet direct dependencies detected for IPU_BRIDGE
  Depends on [n]: MEDIA_SUPPORT [=m] && PCI [=y] && MEDIA_PCI_SUPPORT [=y] && (ACPI [=y] || COMPILE_TEST [=y]) && I2C [=n]
  Selected by [m]:
  - VIDEO_INTEL_IPU6 [=m] && MEDIA_SUPPORT [=m] && PCI [=y] && MEDIA_PCI_SUPPORT [=y] && (ACPI [=y] || COMPILE_TEST [=y]) && VIDEO_DEV [=m] && X86 [=y] && X86_64 [=y] && HAS_DMA [=y]

To make it consistent with the other IPU drivers as well as avoid this
warning, change the 'select' into 'depends on'.

Fixes: c70281cc ("media: intel/ipu6: add Kconfig and Makefile")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[Sakari Ailus: Alternatively depend on !IPU_BRIDGE.]
Cc: stable@vger.kernel.org # for v6.10
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>