crypto: stm32 - Fix last sparse warning in stm32_cryp_check_ctr_counter

This patch changes the cast in stm32_cryp_check_ctr_counter from
u32 to __be32 to match the prototype of stm32_cryp_hw_write_iv
correctly.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>