drm/i915: Use bool i915_param.alpha_support

The alpha_support module option can only take one of two values, so
assign it to a boolean type. The only advantage is in pretty printing
via /sys/module/i915/parameters/alpha_support and elsewhere.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170206213608.31328-2-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_params.c

@@ -145,7 +145,7 @@ MODULE_PARM_DESC(enable_psr, "Enable PSR "
 		 "(0=disabled, 1=enabled - link mode chosen per-platform, 2=force link-standby mode, 3=force link-off mode) "
 		 "Default: -1 (use per-chip default)");
 
-module_param_named_unsafe(alpha_support, i915.alpha_support, int, 0400);
+module_param_named_unsafe(alpha_support, i915.alpha_support, bool, 0400);
 MODULE_PARM_DESC(alpha_support,
 	"Enable alpha quality driver support for latest hardware. "
 	"See also CONFIG_DRM_I915_ALPHA_SUPPORT.");

drivers/gpu/drm/i915/i915_params.h

@@ -40,7 +40,6 @@
 	func(int, enable_ppgtt); \
 	func(int, enable_execlists); \
 	func(int, enable_psr); \
-	func(unsigned int, alpha_support); \
 	func(int, disable_power_well); \
 	func(int, enable_ips); \
 	func(int, invert_brightness); \
@@ -52,6 +51,7 @@
 	func(int, edp_vswing); \
 	func(unsigned int, inject_load_failure); \
 	/* leave bools at the end to not create holes */ \
+	func(bool, alpha_support); \
 	func(bool, enable_cmd_parser); \
 	func(bool, enable_hangcheck); \
 	func(bool, fastboot); \