drivers: ele: rng: get random number from ELE

TEE_GenerateRandom() supported by ELE get random command on imx93 & imx91.

Issues in the ELE FW have been found when both, secure and
non-secure worlds

drivers: ele: rng: get random number from ELE

TEE_GenerateRandom() supported by ELE get random command on imx93 & imx91.

Issues in the ELE FW have been found when both, secure and
non-secure worlds are communicating with ELE.

To prevent any issue, rely on RNG software in OPTEE. The compilation of
hw_get_random_bytes() is conditioned by CFG_WITH_SOFTWARE_PRNG.
Set CFG_WITH_SOFTWARE_PRNG=y by default.

With CFG_WITH_SOFTWARE_PRNG enabled in OP-TEE, ELE will not be used
in OP-TEE at runtime and Linux can access the ELE without conflicts.

Signed-off-by: Clement Faure <clement.faure@nxp.com>
Signed-off-by: Olivier Masse <olivier.masse@nxp.com>
Signed-off-by: Sahil Malhotra <sahil.malhotra@nxp.com>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Acked-by: Etienne Carriere <etienne.carriere@foss.st.com>

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