This patch fixes warning and errors found by checkpatch.pl:
* replace asm/acpi.h, asm/io.h and asm/smp.h with linux/acpi.h,
linux/io.h and linux/smp.h respectively
* remove explicit initialization to 0 of a static global variable
* replace printk(KERN_INFO ...) with pr_info
* use tabs instead of spaces for indentation
* arrange comments so that they adhere to Documentation/CodingStyle