platform: Add weak symbol for cdc clock
platform: Add weak symbol for cdc clock

CRs-Fixed: 501718
Change-Id: I534d2a4498594a2c812dccb4aa815d78cfc1f5aa

mozilla-b2g/kernel_lk,Redmi-dev/android_bootable_lk,Redmi-dev/android_bootable_lk,mozilla-b2g/kernel_lk,mozilla-b2g/kernel_lk,Redmi-dev/android_bootable_lk,Redmi-dev/android_bootable_lk,mozilla-b2g/kernel_lk,t2m-foxfone/kernel_lk,t2m-foxfone/kernel_lk,mozilla-b2g/kernel_lk,Redmi-dev/android_bootable_lk,t2m-foxfone/kernel_lk,t2m-foxfone/kernel_lk,t2m-foxfone/kernel_lk