staging: csr: Remove CsrThreadHandle

CsrThreadHandle is typedef of struct CsrThread.
Some functions in csr_framework_ext.h use it as parameter.
But, nobody call them.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>