Added some missing formats like DXGI_FORMAT_B8G8R8A8_UNORM to GetBitsPerPixel Fixes https://github.com/GPUOpen-LibrariesAndSDKs/D3D12MemoryAllocator/issues/88

diff --git a/src/D3D12MemAlloc.cpp b/src/D3D12MemAlloc.cpp
index fea7981..ce47be6 100644
--- a/src/D3D12MemAlloc.cpp
+++ b/src/D3D12MemAlloc.cpp

@@ -703,6 +703,10 @@
     case DXGI_FORMAT_R24_UNORM_X8_TYPELESS:

     case DXGI_FORMAT_X24_TYPELESS_G8_UINT:

         return 32;

+    case DXGI_FORMAT_B8G8R8A8_UNORM:

+    case DXGI_FORMAT_B8G8R8X8_UNORM:

+    case DXGI_FORMAT_B8G8R8X8_UNORM_SRGB:

+        return 32;

     case DXGI_FORMAT_R8G8_TYPELESS:

     case DXGI_FORMAT_R8G8_UNORM:

     case DXGI_FORMAT_R8G8_UINT:

@@ -717,6 +721,9 @@
     case DXGI_FORMAT_R16_SNORM:

     case DXGI_FORMAT_R16_SINT:

         return 16;

+    case DXGI_FORMAT_B5G6R5_UNORM:

+    case DXGI_FORMAT_B5G5R5A1_UNORM:

+        return 16;

     case DXGI_FORMAT_R8_TYPELESS:

     case DXGI_FORMAT_R8_UNORM:

     case DXGI_FORMAT_R8_UINT: