drm/xe: Define XE_REG_OPTION_VF

We will tag registers that SR-IOV Virtual Functions can access.
This will help us catch any invalid usage and/or provide custom
replacement if available.
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240314173130.1177-3-michal.wajdeczko@intel.comSigned-off-by: Michał Winiarski <michal.winiarski@intel.com>

drivers/gpu/drm/xe/regs/xe_reg_defs.h

@@ -37,6 +37,10 @@ struct xe_reg {
 			 * value can inspect it.
 			 */
 			u32 mcr:1;
+			/**
+			 * @vf: register is accessible from the Virtual Function.
+			 */
+			u32 vf:1;
 			/**
 			 * @ext: access MMIO extension space for current register.
 			 */
@@ -78,6 +82,13 @@ struct xe_reg_mcr {
  */
 #define XE_REG_OPTION_MASKED		.masked = 1
 
+/**
+ * XE_REG_OPTION_VF - Register is "VF" accessible.
+ *
+ * To be used with XE_REG() and XE_REG_INITIALIZER().
+ */
+#define XE_REG_OPTION_VF		.vf = 1
+
 /**
  * XE_REG_INITIALIZER - Initializer for xe_reg_t.
  * @r_: Register offset