The libcrypto and libssl modules (and their respective static and host
versions) use LOCAL_EXPORT_C_INCLUDE_DIRS thus just including the module
is sufficient.
Additionally, cryptfs.h was including an OpenSSL header just to get the
length of a SHA-256 hash. Rather than force all users of this header to
also depend on libcrypto, it's easier just to define that value in the
header file.
Change-Id: I3e3e0db906a212e1093944b298e4a8ff2e2fb07d