Remove alpha from hwc_layer_t

The addition of alpha to hwc_layer_t made it binary incompatible
with the upstream AOSP

Change-Id: Ic85f83c4dda986cb5797896c879a33f8422d0261

patch/ics_strawberry/frameworks/base/surfaceflinger_remove_layer_alpha.patch

+diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
+index 162c241..94630c2 100644
+--- a/services/surfaceflinger/Layer.cpp
++++ b/services/surfaceflinger/Layer.cpp
+@@ -200,8 +200,6 @@ void Layer::setGeometry(hwc_layer_t* hwcl)
+         }
+     }
+ 
+-    hwcl->alpha = s.alpha;
+-
+     /*
+      * Transformations are applied in this order:
+      * 1) buffer orientation/flip/mirror

patch/ics_strawberry/hardware/libhardware/hwc_header_remove_layer_alpha.patch

+diff --git a/include/hardware/hwcomposer.h b/include/hardware/hwcomposer.h
+index 1b77733..d53269f 100644
+--- a/include/hardware/hwcomposer.h
++++ b/include/hardware/hwcomposer.h
+@@ -169,9 +169,6 @@ typedef struct hwc_layer {
+     /* blending to apply during composition */
+     int32_t blending;
+ 
+-    /* alpha value of the layer */
+-    int32_t alpha;
+-
+     /* area of the source to consider, the origin is the top-left corner of
+      * the buffer */
+     hwc_rect_t sourceCrop;

patch/ics_strawberry/hardware/qcom/display/hwc_impl_remove_layer_alpha.patch

+diff --git a/libhwcomposer/a-family/hwcomposer.cpp b/libhwcomposer/a-family/hwcomposer.cpp
+index 378870f..6ab47f0 100644
+--- a/libhwcomposer/a-family/hwcomposer.cpp
++++ b/libhwcomposer/a-family/hwcomposer.cpp
+@@ -1624,8 +1624,7 @@ static int drawLayerUsingCopybit(hwc_composer_device_t *dev, hwc_layer_t *layer,
+             hwc_region_t tmp_hwc_reg = {1,(hwc_rect_t const*)&tmp_hwc_rect};
+             region_iterator tmp_it(tmp_hwc_reg);
+             copybit->set_parameter(copybit,COPYBIT_TRANSFORM,0);
+-            copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA,
+-                        (layer->blending == HWC_BLENDING_NONE) ? -1 : layer->alpha);
++            copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, 255);
+             err = copybit->stretch(copybit,&tmp_dst, &src, &tmp_rect, &srcRect, &tmp_it);
+             if(err < 0){
+                 LOGE("%s:%d::tmp copybit stretch failed",__FUNCTION__,__LINE__);
+@@ -1659,8 +1658,7 @@ static int drawLayerUsingCopybit(hwc_composer_device_t *dev, hwc_layer_t *layer,
+     copybit->set_parameter(copybit, COPYBIT_FRAMEBUFFER_WIDTH, renderBuffer->width);
+     copybit->set_parameter(copybit, COPYBIT_FRAMEBUFFER_HEIGHT, renderBuffer->height);
+     copybit->set_parameter(copybit, COPYBIT_TRANSFORM, layerTransform);
+-    copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA,
+-                           (layer->blending == HWC_BLENDING_NONE) ? -1 : layer->alpha);
++    copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, 255);
+     copybit->set_parameter(copybit, COPYBIT_PREMULTIPLIED_ALPHA,
+                            (layer->blending == HWC_BLENDING_PREMULT)? COPYBIT_ENABLE : COPYBIT_DISABLE);
+     copybit->set_parameter(copybit, COPYBIT_DITHER,