Update on "[ET-VK] Using uint16 for quantized linear tiling shader to reduce register pressure and improve performance."

This diff reduces int precision for certain variables in 8 bit quantized tiled linear op to reduce register pressure and improve performance.

Differential Revision: [D73752090](https://our.internmc.facebook.com/intern/diff/D73752090/)

[ghstack-poisoned]

Author: trivedivivek