x86: acpi: Set the log category for x86 table generation

This file doesn't currently have a log category. Add one so that items
are logged correctly.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NBin Meng <bmeng.cn@gmail.com>

arch/x86/lib/acpi_table.c

@@ -6,6 +6,8 @@
  * Copyright (C) 2016, Bin Meng <bmeng.cn@gmail.com>
  */
 
+#define LOG_CATEGORY LOGC_ACPI
+
 #include <common.h>
 #include <bloblist.h>
 #include <cpu.h>