Add minimal support for readPixels in raster F16

src/core/SkConfig8888.cpp

Index: src/core/SkConfig8888.cpp
diff --git a/src/core/SkConfig8888.cpp b/src/core/SkConfig8888.cpp
index 5bac16a2728e387631942917bee2e181ed465f8d..31def9a92d81f54118823baf35863500d03a4e53 100644
--- a/src/core/SkConfig8888.cpp
+++ b/src/core/SkConfig8888.cpp
@@ -215,6 +215,7 @@ bool SkPixelInfo::CopyPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t
                 break;
             case kIndex_8_SkColorType:
             case kARGB_4444_SkColorType:
+            case kRGBA_F16_SkColorType:
                 if (srcInfo.alphaType() != dstInfo.alphaType()) {
                     return false;
                 }