drm/i915: Make lspcon_init() static

Make lspcon_init() static since it's no longer needed outside
the compilation unit. This was correct in Kai-Heng's lspcon
patch, but I fumbled this when applying it.

Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reported-by: kernel test robot <lkp@intel.com>
Fixes: f542d671 ("drm/i915: Init lspcon after HPD in intel_dp_detect()")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201002090446.21104-1-ville.syrjala@linux.intel.comReviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

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

@@ -530,7 +530,7 @@ void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon)
 	lspcon_wait_mode(lspcon, DRM_LSPCON_MODE_PCON);
 }
 
-bool lspcon_init(struct intel_digital_port *dig_port)
+static bool lspcon_init(struct intel_digital_port *dig_port)
 {
 	struct intel_dp *dp = &dig_port->dp;
 	struct intel_lspcon *lspcon = &dig_port->lspcon;