Looks like it's just missing #include <linux/io.h>
Unfortunately there are more errors ahead:
/home/kiroma/AMDPowerProfiler-8.00/src/PwrProfModule.c: In function ‘PwrProfInitModule’:
/home/kiroma/AMDPowerProfiler-8.00/src/PwrProfModule.c:207:51: error: passing argument 4 of ‘proc_create’ from incompatible pointer type [-Werror=incompatible-pointer-types]
207 | Entries[entry_created].proc_fops);
| ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
| |
| const struct file_operations *
In file included from /home/kiroma/AMDPowerProfiler-8.00/src/PwrProfModule.c:16:
/usr/src/linux-5.6.12-1/include/linux/proc_fs.h:64:24: note: expected ‘const struct proc_ops *’ but argument is of type ‘const struct file_operations *’
64 | struct proc_dir_entry *proc_create(const char *name, umode_t mode, struct proc_dir_entry *parent, const struct proc_ops *proc_ops);
| ^~~~~~~~~~~