Consistently use the name tinycrypt over uecc

We called in tinycrypt in the file names, but uecc in config.h, all.sh and
other places, which could be confusing. Just use tinycrypt everywhere because
that's the name of the project and repo where we took the files.

The changes were made using the following commands (with GNU sed and zsh):

sed -i 's/uecc/tinycrypt/g' **/*.[ch] tests/scripts/all.sh
sed -i 's/MBEDTLS_USE_UECC/MBEDTLS_USE_TINYCRYPT/g' **/*.[ch] tests/scripts/all.sh scripts/config.pl
diff --git a/tinycrypt/ecc_dh.c b/tinycrypt/ecc_dh.c
index 5d0a52f..28dfdf9 100644
--- a/tinycrypt/ecc_dh.c
+++ b/tinycrypt/ecc_dh.c
@@ -54,7 +54,7 @@
  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  *  POSSIBILITY OF SUCH DAMAGE.
  */
-#if defined(MBEDTLS_USE_UECC)
+#if defined(MBEDTLS_USE_TINYCRYPT)
 #include <tinycrypt/ecc.h>
 #include <tinycrypt/ecc_dh.h>
 #include <string.h>
@@ -197,5 +197,5 @@
 	return r;
 }
 #else
-typedef int mbedtls_dummy_uecc_def;
-#endif /* MBEDTLS_USE_UECC */
+typedef int mbedtls_dummy_tinycrypt_def;
+#endif /* MBEDTLS_USE_TINYCRYPT */