hw_random: add support for STM32 RNG ...

Port over the U-Boot v2020.01.0 state of the driver.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

hwrng: add sandbox driver interface to host /dev/random ...

Linux as well as other operating systems can provide /dev/random and
/dev/urandom device to service userspace need for randomness.
Add a driver to use /dev/random for blocking and /dev/urandom for
non-blocking barebox random numbers.

Signed-off-by: Ahmad Fatoum <ahmad@a3f.at>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

hw_random: add driver for Freescale RNGC ...

The driver is ported from Freescales Linux git and can be
found in the

	vendor/freescale/imx_2.6.35_maintain

branch.

According to that code, the RNGC is found on Freescales i.MX3/5 SoCs.
The i.MX2x actually has an RNGB, which has no driver implementation
in Freescales kernel. However as it turns out, the driver for the RNGC
works fine on the (at least) i.MX25. So, they seem to be somewhat
compatible.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>

drivers: add simple hw_random implementation ...

Add a simple hw_random implementation based on code from
Linux v4.5-rc5.

All the entropypool initialization stuff is left out and
the obsolete data_read/data_present calls are omitted.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>