mips: Add reserve-nomap memory type support

It might be necessary to prevent the virtual mapping creation for a
requested memory region. For instance there is a "no-map" property
indicating exactly this feature. In this case we need to not only
reserve the specified region by pretending it doesn't exist in the
memory space, but completely remove the range from system just by
removing it from memblock. The same way it's done in default
early_init_dt_reserve_memory_arch() method.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Matt Redfearn <matt.redfearn@mips.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

arch/mips/include/asm/bootinfo.h

@@ -92,6 +92,7 @@ extern unsigned long mips_machtype;
 #define BOOT_MEM_ROM_DATA	2
 #define BOOT_MEM_RESERVED	3
 #define BOOT_MEM_INIT_RAM	4
+#define BOOT_MEM_NOMAP		5
 
 /*
  * A memory map that's built upon what was determined