Add dhex_dump() and DHEXDUMP() to format and print data in hexadecimal
OpenSSL crypto provider: implement TEE_ALG_RSA_NOPAD

Sub-tests 1 to 4 of xtest 4006 are OK.
OpenSSL crypto provider: implement RSA signing (TEE_ALG_RSASSA*).

This adds support for the following algorithms:
TEE_ALG_RSASSA_PKCS1_V1_5_MD5, TEE_ALG_RSASSA_PKCS1_V1_5_SHA1,
TEE_ALG_RSASSA_PKCS1_V1_5_SHA224, TEE_ALG_RSASSA_PKCS1_V1_5_SHA256,
TEE_ALG_RSASSA_PKCS1_V1_5_SHA384, TEE_ALG_RSASSA_PKCS1_V1_5_SHA512,
TEE_ALG_RSASSA_PKCS1_PSS_MGF1_SHA1, TEE_ALG_RSASSA_PKCS1_PSS_MGF1_SHA224,
TEE_ALG_RSASSA_PKCS1_PSS_MGF1_SHA256, TEE_ALG_RSASSA_PKCS1_PSS_MGF1_SHA384,
TEE_ALG_RSASSA_PKCS1_PSS_MGF1_SHA512.

Tested with xtest 4006 on FVP. Sub-tests 5 to 34 are successful.
Trace OpenSSL errors with EMSG() as they occur.
OpenSSL crypto provider: implement TEE_ALG_RSAES_PKCS1_*

This adds support for:
TEE_ALG_RSAES_PKCS1_V1_5, TEE_ALG_RSAES_PKCS1_OAEP_MGF1_SHA1,
TEE_ALG_RSAES_PKCS1_OAEP_MGF1_SHA224, TEE_ALG_RSAES_PKCS1_OAEP_MGF1_SHA256,
TEE_ALG_RSAES_PKCS1_OAEP_MGF1_SHA384, TEE_ALG_RSAES_PKCS1_OAEP_MGF1_SHA512.

Tested with xtest 4006 on FVP. Sub-tests 35 to 82 are successful.
OpenSSL crypto provider: implement TEE_ALG_DSA_SHA1

This commmit also adds functions for DSA key allocation and generation.
OpenSSL crypto provider: fix crash during DSA key generation

Fixes xtest 4007.1 to 4007.10.
plat-vexpress: build with -mfloat-abi=soft

OP-TEE on plat-vexpress does not support Neon. This patch prevents generating
Neon instructions when the cross-compiler is configured to use
'-mfloat-abi=hard' by default (such as arm-linux-gnueabihf-gcc).
OpenSSL crypto provider: revert RAND_add() kludge

Now that we build with -mfloat-abi=soft when the platform does not support
Neon, RAND_add() can be a no-op function rather than a macro.
[In hard float mode, the compiler would generate a 'vldr' instruction, which
would cause an undefined instruction exception on the Foundation_v8 FVP.]
Use int instead of bool
OpenSSL crypto provider: implement DH key generation and derivation

Tested on Foundation_v8 FVP with xtest 4007.19 to 4007.48 (key generation)
and xtest 4008 (key derivation).