pata_platform: __pata_platform_remove() shouldn't be in discard section

--
  UPD     include/linux/compile.h
`___pata_platform_remove' referenced in section `__ksymtab_gpl' of
drivers/built-in.o: defined in discarded section `.devexit.text' of
drivers/built-in.o
make: *** [.tmp_vmlinux1] Error 1
--

__pata_platform_remove() should not be in discarded section
__pata_platform_remove(struct device *dev) is invoked in both
pata_platform.c and pata_of_platform.c by reomve function defined in
discarded section ".devexit.text". An exported function should not be put
into discarded section.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>