drm: zynqmp_dp: Fix integer overflow in zynqmp_dp_rate_get()
In the Linux kernel, the following vulnerability has been resolved:

drm: zynqmp_dp: Fix integer overflow in zynqmp_dp_rate_get()

This patch fixes a potential integer overflow in the zynqmp_dp_rate_get()

The issue comes up when the expression
drm_dp_bw_code_to_link_rate(dp->test.bw_code) * 10000 is evaluated using 32-bit
Now the constant is a compatible 64-bit type.

Resolves coverity issues: CID 1636340 and CID 1635811