ARM: Add ARM architecture detection to generic bootloader ARM code.

This detects everything up to ARMv6 right now. Need to check more
recent ARM ARMs for ARMv7 detection.

The detected details get passed on to the kernel, which can use
the pre-detected info for selecting right pagetable format and such.

Copyright removal of Axel done after agreement with Axel @ BeGeistert
that for files that were copy/pasted from x86 arch and then fully
replaced the implementation, removal of original copyright holder is
allowed, since their actual code is gone ;)

headers/private/kernel/arch/arm/arch_cpu.h

@@ -33,14 +33,29 @@ struct iframe {
 	uint32 pc;
 } _PACKED;
 
-typedef struct arch_cpu_info {
-} arch_cpu_info;
+/**! Values for arch_cpu_info.arch */
+enum {
+	ARCH_ARM_PRE_ARM7,
+	ARCH_ARM_v3,
+	ARCH_ARM_v4,
+	ARCH_ARM_v4T,
+	ARCH_ARM_v5,
+	ARCH_ARM_v5T,
+	ARCH_ARM_v5TE,
+	ARCH_ARM_v5TEJ,
+	ARCH_ARM_v6
+};
 
-extern int arch_cpu_type;
-extern int arch_fpu_type;
-extern int arch_mmu_type;
-extern int arch_platform;
-extern int arch_machine;
+typedef struct arch_cpu_info {
+	/* For a detailed interpretation of these values,
+	   see "The System Control coprocessor",
+	   "Main ID register" in your ARM ARM */
+	int implementor;
+	int part_number;
+	int revision;
+	int variant;
+	int arch;
+} arch_cpu_info;
 
 #ifdef __cplusplus
 extern "C" {