soc: st: stm32: add support for stm32f439

STM32F439 SoC is an STM32F429 with an integrated crypto/hash processor
providing hardware acceleration for encryption (AES and TDES) and hash
(MD5, SHA-1 and SHA-2).

Signed-off-by: Mathieu Anquetin <mathieu.anquetin@groupe-cahors.com>