drm/i915/bios: Fix ports mask

PORT_A to PORT_F are regular integers defined in the enum port,
while for_each_port_masked requires a bit mask for the ports.

Current given mask: 0b111
Desired mask: 0b111111

I noticed this while Christoph was reporting a bug found on headless
GVT configuration which bisect blamed commit 3ae04c0c ("drm/i915/bios:
limit default outputs to ports A through F")

v2: Avoid unnecessary line continuations as pointed by CI and Christoph

Cc: Christoph Hellwig <hch@infradead.org>
Fixes: 3ae04c0c ("drm/i915/bios: limit default outputs to ports A through F")
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: NJosé Roberto de Souza <jose.souza@intel.com>
Reviewed-by: NLucas De Marchi <lucas.demarchi@intel.com>
Tested-by: NChristoph Hellwig <hch@infradead.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723095225.562913-1-rodrigo.vivi@intel.com

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

@@ -2166,7 +2166,8 @@ static void
 init_vbt_missing_defaults(struct drm_i915_private *i915)
 {
 	enum port port;
-	int ports = PORT_A | PORT_B | PORT_C | PORT_D | PORT_E | PORT_F;
+	int ports = BIT(PORT_A) | BIT(PORT_B) | BIT(PORT_C) |
+		    BIT(PORT_D) | BIT(PORT_E) | BIT(PORT_F);
 
 	if (!HAS_DDI(i915) && !IS_CHERRYVIEW(i915))
 		return;