omap1: Fix DSP public peripherals support for ams-delta

DSP public peripherals used to work on OMAP1510 based (or all OMAP1 class?)
machines as long as old dspgateway code were present in the l-o tree. For
several months it is no longer included, breaking support for McBSP1 based
audio on Amstrad Delta, for example.

This patch, derived from the old dspgateway code, corrects the problem for the
board by simply taking the DSP out of reset state, I guess. That way, things
should not break when a new dsp code is added to the tree, and the change can
be reverted then.

If there are any reports on McBSP1 or other DSP public peripherals not working
for other OMAP1 machines (I've not heard of any for now), I can prepare a more
general patch providing an extra include file with a helper function defined.

Created and tested against linux-2.6.32-rc5

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Tony Lindgren <tony@atomide.com>