x86/boot/e820: Introduce 'enum e820_type'

Use an enum instead of CPP #define.

Also fix various small annoyances in the descriptions of the
various E820 types.

No change in functionality.

Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/e820/types.h

 #ifndef _ASM_E820_TYPES_H
 #define _ASM_E820_TYPES_H
 
+enum e820_type {
+	E820_RAM		= 1,
+	E820_RESERVED		= 2,
+	E820_ACPI		= 3,
+	E820_NVS		= 4,
+	E820_UNUSABLE		= 5,
+	E820_PMEM		= 7,
+
+	/*
+	 * This is a non-standardized way to represent ADR or
+	 * NVDIMM regions that persist over a reboot.
+	 *
+	 * The kernel will ignore their special capabilities
+	 * unless the CONFIG_X86_PMEM_LEGACY=y option is set.
+	 *
+	 * ( Note that older platforms also used 6 for the same
+	 *   type of memory, but newer versions switched to 12 as
+	 *   6 was assigned differently. Some time they will learn... )
+	 */
+	E820_PRAM		= 12,
+
+	/*
+	 * Reserved RAM used by the kernel itself if
+	 * CONFIG_INTEL_TXT=y is enabled, memory of this type
+	 * will be included in the S3 integrity calculation
+	 * and so should not include any memory that the BIOS
+	 * might alter over the S3 transition:
+	 */
+	E820_RESERVED_KERN	= 128,
+};
+
 #include <uapi/asm/e820/types.h>
 
 /*
@@ -39,32 +70,6 @@
 /* Number of entries in E820MAP: */
 #define E820NR			0x1e8
 
-#define E820_RAM		1
-#define E820_RESERVED		2
-#define E820_ACPI		3
-#define E820_NVS		4
-#define E820_UNUSABLE		5
-#define E820_PMEM		7
-
-/*
- * This is a non-standardized way to represent ADR or NVDIMM regions that
- * persist over a reboot.  The kernel will ignore their special capabilities
- * unless the CONFIG_X86_PMEM_LEGACY option is set.
- *
- * ( Note that older platforms also used 6 for the same type of memory,
- *   but newer versions switched to 12 as 6 was assigned differently.  Some
- *   time they will learn... )
- */
-#define E820_PRAM		12
-
-/*
- * reserved RAM used by kernel itself
- * if CONFIG_INTEL_TXT is enabled, memory of this type will be
- * included in the S3 integrity calculation and so should not include
- * any memory that BIOS might alter over the S3 transition
- */
-#define E820_RESERVED_KERN	128
-
 /*
  * The whole array of E820 entries:
  */