crypto: hisilicon/trng - support tfms sharing the device

crypto: hisilicon/trng - support tfms sharing the device

Since the number of devices is limited, and the number
of tfms may exceed the number of devices, to ensure that
tfms can be successfully allocated, support tfms
sharing the same device.

Fixes: e4d9d10ef4be ("crypto: hisilicon/trng - add support for PRNG")
Signed-off-by: Weili Qian <qianweili@huawei.com>
Signed-off-by: Chenghai Huang <huangchenghai2@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>