hwrng: ba431 - use dev_err_probe after failed registration

Use dev_err_probe to print the error message after a failed hwrng
registration.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: ba431 - don't init of_device_id's data

We have no device-specific data for silex-insight,ba431-rng. There's no
need to set .data = NULL, this is the default.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: ba431 - do not set drvdata

Do not set drvdata in the ba431 driver. Nobody is using it.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: ba431 - use devm_platform_ioremap_resource() to simplify

Use devm_platform_ioremap_resource() to simplify the code.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: ba431 - Use device-managed registration

Use device-managed registration, so we can delete the ba431_trng_remove.

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: ba431 - Include kernel.h

There are multiple things in this file that requires kernel.h but
it's only included through other header files indirectly. This
patch adds a direct inclusion as those indirect inclusions may go
away at any point.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

hwrng: ba431 - add support for BA431 hwrng

Silex insight BA431 is an IP designed to generate random numbers that
can be integrated in various FPGA.
This driver adds support for it through the hwrng interface.

This driver is used in Silex Insight Viper OEM boards.

Signed-off-by: Olivier Sobrie <olivier.sobrie@silexinsight.com>
Signed-off-by: Waleed Ziad <waleed94ziad@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>