cpuid_vendor_id.mod.c: make use of enum

c-programming/sys/cpuid_vendor_id.mod.c

@@ -25,10 +25,12 @@
 
 typedef unsigned int cpuid_t[4];
 
-#define EAX 0
-#define EBX 1
-#define ECX 2
-#define EDX 3
+enum CPU_registers {
+	EAX = 0,
+	EBX,
+	ECX,
+	EDX
+};
 
 // https://elixir.bootlin.com/linux/latest/source/arch/x86/include/asm/
 // processor.h#L216