Updated and typo-fixed |SHA| API names on tinydtls module

Updated and typo-fixed |SHA| API names on tinydtls module

this change is for updating the fixed |tinydtls-sha| API names
and correcting the missed typo on its API names. this change
was reviewed finally by Mr. Olaf Bergmann and Mr. Craig Pratt,
who maintain |eclipse-tinydtls|.

Change-Id: I9d4eb21ab5d507726b2dda0b3f27bfa0264b0565
Signed-off-by: Kyungsun Cho <goodsun.cho@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/8231
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Craig Pratt <craig@ecaspia.com>
Reviewed-by: Randeep Singh <randeep.s@samsung.com>