drm/mediatek: Fix coverity issue with unintentional integer overflow

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: drm/mediatek: Fix coverity issue with unintentional integer overflow 1. Instead of multiplying 2 variable of different types. Change to assign a value of one variable and then multiply the other variable. 2. Add a int variable for multiplier calculation instead of calculating different types multiplier with dma_addr_t variable directly.

References

• https://git.kernel.org/stable/c/a12bd675100531f9fb4508fd4430dd1632325a0e
• https://git.kernel.org/stable/c/0d8a1df39d3fc34560e2cc663b5c340d06a25396
• https://git.kernel.org/stable/c/96312a251d4dcee5d36e32edba3002bfde0ddd9c
• https://git.kernel.org/stable/c/b0b0d811eac6b4c52cb9ad632fa6384cf48869e7