crypto: ux500/hash - delete driver

It turns out we can just modify the newer STM32 HASH driver
to be used with Ux500 and now that we have done that, delete
the old and sparsely maintained Ux500 HASH driver.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>