drm/i915/tgl: Fix missing parentheses on TGL_TRANS_DDI_FUNC_CTL_VAL_TO_PORT

In this case we want to apply the mask and then shift so the
parentheses is needed.

SPANK! SPANK! SPANK! Naughty programmer!

Fixes: 9749a5b6 ("drm/i915/tgl: Fix the read of the DDI that transcoder is attached to")
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190812175405.14479-1-jose.souza@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -9433,7 +9433,7 @@ enum skl_power_gate {
 #define  TRANS_DDI_SELECT_PORT(x)	((x) << TRANS_DDI_PORT_SHIFT)
 #define  TGL_TRANS_DDI_SELECT_PORT(x)	(((x) + 1) << TGL_TRANS_DDI_PORT_SHIFT)
 #define  TRANS_DDI_FUNC_CTL_VAL_TO_PORT(val)	 (((val) & TRANS_DDI_PORT_MASK) >> TRANS_DDI_PORT_SHIFT)
-#define  TGL_TRANS_DDI_FUNC_CTL_VAL_TO_PORT(val) (((val) & TGL_TRANS_DDI_PORT_MASK >> TGL_TRANS_DDI_PORT_SHIFT) - 1)
+#define  TGL_TRANS_DDI_FUNC_CTL_VAL_TO_PORT(val) ((((val) & TGL_TRANS_DDI_PORT_MASK) >> TGL_TRANS_DDI_PORT_SHIFT) - 1)
 #define  TRANS_DDI_MODE_SELECT_MASK	(7 << 24)
 #define  TRANS_DDI_MODE_SELECT_HDMI	(0 << 24)
 #define  TRANS_DDI_MODE_SELECT_DVI	(1 << 24)