phy: ti: gmii-sel: check of_get_address() for failure

stable inclusion
from stable-5.10.80
commit fd056574a7e8322c847b458cfe7c1343dcc32497
bugzilla: 185821 https://gitee.com/openeuler/kernel/issues/I4L7CG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fd056574a7e8322c847b458cfe7c1343dcc32497



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

[ Upstream commit 8d55027f ]

Smatch complains that if of_get_address() returns NULL, then "size"
isn't initialized.  Also it would lead to an Oops.

Fixes: 7f78322c ("phy: ti: gmii-sel: retrieve ports number and base offset from dt")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Link: https://lore.kernel.org/r/20210914110038.GB11657@kili


Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Reviewed-by: Weilong Chen <chenweilong@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>

Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>