staging: rts5139: add vmalloc.h to some files to fix the build.

This is needed to fix the build on alpha and ppc at the least.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: edwin_rong <edwin_rong@realsil.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>