tee: optee: Use kmemdup() to replace kmalloc + memcpy

Use kmemdup rather than duplicating its implementation.

./drivers/tee/optee/smc_abi.c:1542:12-19: WARNING opportunity for kmemdup.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=5480


Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>