crypto: ecc - Export additional helper functions

Export the following additional ECC helper functions:
- ecc_alloc_point()
- ecc_free_point()
- vli_num_bits()
- ecc_point_is_zero()

This is done to allow future ECC device drivers to re-use existing code,
thus simplifying their implementation.

Functions are exported using EXPORT_SYMBOL() (instead of
EXPORT_SYMBOL_GPL()) to be consistent with the functions already
exported by crypto/ecc.c.

Exported functions are documented in include/crypto/internal/ecc.h.

Signed-off-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: ecc - Move ecc.h to include/crypto/internal

Move ecc.h header file to 'include/crypto/internal' so that it can be
easily imported from everywhere in the kernel tree.

This change is done to allow crypto device drivers to re-use the symbols
exported by 'crypto/ecc.c', thus avoiding code duplication.

Signed-off-by: Daniele Alessandrelli <daniele.alessandrelli@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>