drm/i915/display: Make intel_dp_aux_fw_sync_len available for PSR code

ALPM AUX-Wake fast wake sync pulse count is needed by PSR to calculate IO
wake and fast wake lines. Convert intel_dp_aux_fw_sync_len as non-static
to make it available for PSR code.

v2: use int instead of u8
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240313133221.868391-2-jouni.hogander@intel.com

drivers/gpu/drm/i915/display/intel_dp_aux.c

@@ -143,7 +143,7 @@ static int intel_dp_aux_sync_len(void)
 	return precharge + preamble;
 }
 
-static int intel_dp_aux_fw_sync_len(void)
+int intel_dp_aux_fw_sync_len(void)
 {
 	int precharge = 10; /* 10-16 */
 	int preamble = 8;

drivers/gpu/drm/i915/display/intel_dp_aux.h

@@ -20,5 +20,6 @@ enum aux_ch intel_dp_aux_ch(struct intel_encoder *encoder);
 
 void intel_dp_aux_irq_handler(struct drm_i915_private *i915);
 u32 intel_dp_aux_pack(const u8 *src, int src_bytes);
+int intel_dp_aux_fw_sync_len(void);
 
 #endif /* __INTEL_DP_AUX_H__ */