drm/xe/vram: fix ccs offset calculation

drm/xe/vram: fix ccs offset calculation

Spec says SW is expected to round up to the nearest 128K, if not already
aligned for the CC unit view of CCS. We are seeing the assert sometimes
pop on BMG to tell us that there is a hole between GSM and CCS, as well
as popping other asserts with having a vram size with strange alignment,
which is likely caused by misaligned offset here.

v2 (Shuicheng):
 - Do the round_up() on final SW address.

BSpec: 68023
Fixes: b5c2ca0372dc ("drm/xe/xe2hpg: Determine flat ccs offset for vram")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Cc: Akshata Jahagirdar <akshata.jahagirdar@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Shuicheng Lin <shuicheng.lin@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: stable@vger.kernel.org # v6.10+
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Tested-by: Shuicheng Lin <shuicheng.lin@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240916084911.13119-2-matthew.auld@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>