pata_hpt37x: Fix 2.6.22 clock PLL regression

	Just one version of Linux ago
	The PLL code broke - oh no!
	But set the right mode
	And fix up the code
	Makes the PLL timing sync go

[whatever happened to the sailor from Nantucket, hero of many limericks?  -jg]

Closes-bug: #8791
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>