busdma - Remove filter functionality

- Remove filtfunc and filtarg arguments from bus_dma_tag_create() and
fix all callers. All callers use NULL today for both filterfunc and
filterarg with one

busdma - Remove filter functionality

- Remove filtfunc and filtarg arguments from bus_dma_tag_create() and
fix all callers. All callers use NULL today for both filterfunc and
filterarg with one exception: if_jme.

- Remove filter functionality internally and parent tag tracking.
Without filter functions, we do not need to keep track of tag
ancestry. All inheritance of the parent tag's parameters occurs when
creating the new child tag.

- rename run_filter() to addr_needs_bounce().

- FreeBSD keeps the filtfunc and filtarg arguments but requires them to
be NULL.

- Drop filterfunc usage from if_jme.

In case of "JMC260 chip full mask revision 2", which has a hardware bug
when it comes to DMA transfers crossing the 4 GB bounday, the parent
buffer tag already limits DMA memory to 32bit address space. As such it
should be safe to drop the filterfunc. The filterfunc was checking if
the lower 32bits of the physical address used for DMA are all 0. In case
of a 32bit address space, the only address where all lower 32-bits are
all zero is 0 itself and I am here assuming that the physical address 0
is not used for DMA transfers!

Mainly obtained from: FreeBSD (commits 7cb028de, 900907f4, 1228b93b, 3933ff56)

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kernel: Rename BUILDING_WITH_KERNEL to KERNBUILDDIR.

Fits better with e.g. KERNCONFDIR.

Add a small paragraph in kmod.mk which was taken from FreeBSD.