really fixed channel queue problems. The adc enable bit does not need

really fixed channel queue problems.  The adc enable bit does not need
to be set during setup after all.  Fixed random problems with first
dma block by adding a little more dma initialization during command
setup.  Fixed two bogus samples on first command using external
queue by moving queue setup to a later point in ai cmd.  Moved around
some code in attach() so more stuff gets done before interrupt
handler is registered (due to one crash I saw while modprobing
while sound card on same interrupt was playing).