aes: use integer types with explicit size
aes: use integer types with explicit size

An int is just at least 16 bytes long and not 32 bytes on all systems.
Here we need integers with an explicit size therefor we should use
uint**_t. This makes the code compile for a 16 bit CPU.

Signed-off-by: Hauke Mehrtens <435ddd46dc66c007a1fa20144c823d37e0d23436@hauke-m.de>

fvdnabee/tinydtls,thecodemaiden/tinydtls-fork,OlegHahm/tinydtls,nmacs/tinydtls,thecodemaiden/tinydtls-fork,OlegHahm/tinydtls,jvermillard/tinydtls,OlegHahm/tinydtls,spark/tinydtls,yunus/TinyDTLS-WebID,nmacs/tinydtls,spark/tinydtls,nmacs/tinydtls,jvermillard/tinydtls,jvermillard/tinydtls,spark/tinydtls,thecodemaiden/tinydtls-fork,fvdnabee/tinydtls,yunus/TinyDTLS-WebID,nmacs/tinydtls,fvdnabee/tinydtls,yunus/TinyDTLS-WebID