xtensa: add missing symbol exports

commit d3738f407c8ced4fd17dccf6cce729023c735c73 upstream.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
[bwh: Backported to 3.2: drop exports of some functions that aren't defined here]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --cc arch/xtensa/kernel/pci-dma.c
Simple merge

diff --cc arch/xtensa/kernel/xtensa_ksyms.c
Simple merge