ARM: OMAP: Fix export.h or module.h includes

Commit 32aaeffbd4a7457bf2f7448b33b5946ff2a960eb (Merge branch
'modsplit-Oct31_2011'...) caused some build errors. Fix these
and make sure we always have export.h or module.h included
for MODULE_ and EXPORT_SYMBOL users:

$ grep -rl ^MODULE_ arch/arm/*omap*/*.c | xargs \
  grep -L linux/module.h
  arch/arm/mach-omap2/dsp.c
  arch/arm/mach-omap2/mailbox.c
  arch/arm/mach-omap2/omap-iommu.c
  arch/arm/mach-omap2/smartreflex.c

Also check we either have export.h or module.h included
for the files exporting symbols:

$ grep -rl EXPORT_SYMBOL arch/arm/*omap*/*.c | xargs \
  grep -L linux/export.h | xargs grep -L linux/module.h

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>