parisc: Prevent hung tasks when printing inventory on serial console

Printing the inventory on a serial console can be quite slow and thus may
trigger the hung task detector (CONFIG_DETECT_HUNG_TASK=y) and possibly
reboot the machine. Adding a cond_resched() prevents this.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v6.0+