drm/xe: Use USEC_PER_MSEC rather than the hard coding

Use USEC_PER_MSEC rather than the hard coded value of 1000.

Static analyzer Reported "casting either timeout_ms or
1000U to type u64" to avoid overflow-before-widen.
Using USEC_PER_MSEC seems better and will help with static analyzer
report cleanup.

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240320083325.3258720-1-himal.prasad.ghimiray@intel.comSigned-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

drivers/gpu/drm/xe/xe_pcode.c

@@ -74,7 +74,7 @@ static int pcode_mailbox_rw(struct xe_gt *gt, u32 mbox, u32 *data0, u32 *data1,
 	xe_mmio_write32(gt, PCODE_MAILBOX, PCODE_READY | mbox);
 
 	err = xe_mmio_wait32(gt, PCODE_MAILBOX, PCODE_READY, 0,
-			     timeout_ms * 1000, NULL, atomic);
+			     timeout_ms * USEC_PER_MSEC, NULL, atomic);
 	if (err)
 		return err;