drm/xe: Fix out-of-bounds field write in MI_STORE_DATA_IMM

According to Bspec, bits 0~9 of MI_STORE_DATA_IMM must not exceed 0x3FE.
The macro MI_SDI_NUM_QW(x) evaluates to 2 * x + 1, which means the
condition 2 * x + 1 <= 0x3FE must be satisfied. Therefore, the maximum
valid value for x is 0x1FE, not 0x1FF.

v2
 - Replace 0x1fe with macro MAX_PTE_PER_SDI (Auld, Matthew & Patelczyk, Maciej)

v3
 - Change macro MAX_PTE_PER_SDI from 0x1fe to 0x1feU (De Marchi, Lucas)

Bspec: 60246

Fixes: 9c44fd5f ("drm/xe: Add migrate layer functions for SVM support")
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Brian3 Nguyen <brian3.nguyen@intel.com>
Cc: Alex Zuo <alex.zuo@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Maciej Patelczyk <maciej.patelczyk@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Suggested-by: Shuicheng Lin <shuicheng.lin@intel.com>
Signed-off-by: Jia Yao <jia.yao@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Link: https://lore.kernel.org/r/20250612224620.161105-1-jia.yao@intel.com


Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>