[POWERPC] Xilinx uartlite: Section type fixups

All the __devexit functions are now appropriately tagged.  This fixes
some ppc link warnings.

Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>