kernel: kmod-md-multipath: Depend on kernel 6.6

This driver was removed in kernel 6.8 [0], make it depend on kernel 6.6
for now.

[0]: https://git.kernel.org/linus/d8730f0cf4effa015bc5e8840d8f8fb3cdb01aab

Link: https://github.com/openwrt/openwrt/pull/19480
Signed-off-by: Hauke Mehrtens <[email protected]>

package/kernel/linux/modules/block.mk

@@ -419,7 +419,7 @@ $(eval $(call KernelPackage,md-raid456))
 
 
 define KernelPackage/md-multipath
-$(call KernelPackage/md/Depends,)
+$(call KernelPackage/md/Depends,@LINUX_6_6)
   TITLE:=MD Multipath Module
   KCONFIG:=CONFIG_MD_MULTIPATH
   FILES:=$(LINUX_DIR)/drivers/md/multipath.ko