crypto: ccree - improve kerneldoc in cc_request_mgr.[ch]

Miscellaneous improvements:
  - Start comment blocks with "/**" to enable kerneldoc,
  - Mark parameters using "@" instead of "\param",
  - Fix copied is_dout parameter of cc_send_request(),
  - Add missing function names to kerneldoc headers,
  - Add missing parameter descriptions.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>