dmaengine: qcom-adm: fix wrong sizeof config in slave_config

In the Linux kernel, the following vulnerability has been resolved:

dmaengine: qcom-adm: fix wrong sizeof config in slave_config

Fix broken slave_config function that uncorrectly compare the

peripheral_size with the size of the config pointer instead of the size

of the config struct. This cause the crci value to be ignored and cause

a kernel panic on any slave that use adm driver.

To fix this, compare to the size of the struct and NOT the size of the

pointer.