clk: imx: Add check for kcalloc

mainline inclusion
from mainline-v5.19-rc1
commit ed713e2b
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I6698Y
CVE: CVE-2022-3114

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ed713e2bc093239ccd380c2ce8ae9e4162f5c037



--------------------------------

As the potential failure of the kcalloc(),
it should be better to check it in order to
avoid the dereference of the NULL pointer.

Fixes: 379c9a24 ("clk: imx: Fix reparenting of UARTs not associated with stdout")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Link: https://lore.kernel.org/r/20220310080257.1988412-1-jiasheng@iscas.ac.cn


Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Yi Yang <yiyang13@huawei.com>
Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>