apps: define FrameBufferAddr for riscv64

The size of FrameBufferAddr is architecture dependent. Add the missing
definition for the riscv64 architecture.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

apps/lfbgrid.c

@@ -51,7 +51,8 @@ draw_boxes(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop)
 	UINTN NumPixels;
 	UINT32 *PixelBuffer;
 	UINT32 CopySize, BufferSize;
-#if defined(__x86_64__) || defined(__aarch64__)
+#if defined(__x86_64__) || defined(__aarch64__) || \
+    (defined (__riscv) && __riscv_xlen == 64)
 	UINT64 FrameBufferAddr;
 #elif defined(__i386__) || defined(__arm__)
 	UINT32 FrameBufferAddr;
@@ -114,7 +115,8 @@ draw_boxes(EFI_GRAPHICS_OUTPUT_PROTOCOL *gop)
 			Print(L"No linear framebuffer on this device.\n");
 			return;
 		}
-#if defined(__x86_64__) || defined(__aarch64__)
+#if defined(__x86_64__) || defined(__aarch64__) || \
+    (defined (__riscv) && __riscv_xlen == 64)
 		FrameBufferAddr = (UINT64)gop->Mode->FrameBufferBase;
 #elif defined(__i386__) || defined(__arm__)
 		FrameBufferAddr = (UINT32)(UINT64)gop->Mode->FrameBufferBase;