sandbox: Correct guard around readq/writeq

In include/linux/io.h the declarations of ioread64 and iowrite64
which make use of readq/writeq are guarded with CONFIG_64BIT so
guard the sandbox declarations of readq and writeq also with
CONFIG_64BIT.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
diff --git a/arch/sandbox/include/asm/io.h b/arch/sandbox/include/asm/io.h
index 3d09170..f656f36 100644
--- a/arch/sandbox/include/asm/io.h
+++ b/arch/sandbox/include/asm/io.h
@@ -39,13 +39,13 @@
 #define readb(addr) sandbox_read((const void *)addr, SB_SIZE_8)
 #define readw(addr) sandbox_read((const void *)addr, SB_SIZE_16)
 #define readl(addr) sandbox_read((const void *)addr, SB_SIZE_32)
-#ifdef CONFIG_SANDBOX64
+#ifdef CONFIG_64BIT
 #define readq(addr) sandbox_read((const void *)addr, SB_SIZE_64)
 #endif
 #define writeb(v, addr) sandbox_write((void *)addr, v, SB_SIZE_8)
 #define writew(v, addr) sandbox_write((void *)addr, v, SB_SIZE_16)
 #define writel(v, addr) sandbox_write((void *)addr, v, SB_SIZE_32)
-#ifdef CONFIG_SANDBOX64
+#ifdef CONFIG_64BIT
 #define writeq(v, addr) sandbox_write((void *)addr, v, SB_SIZE_64)
 #endif