parisc: Include compressed vmlinux file in vmlinuz boot kernel

Change the parisc vmlinuz boot code to include and process the real
compressed vmlinux.gz ELF file instead of a compressed memory dump.
This brings parisc in sync on how it's done on x86_64.

The benefit of this change is that, e.g. for debugging purposes, one can
then extract the vmlinux file out of the vmlinuz which was booted which
wasn't possible before. This can be archieved with the existing
scripts/extract-vmlinux script, which just needs a small tweak to prefer
to extract a compressed file before trying the existing given binary.

The downside of this approach is that due to the extra round of
decompression/ELF processing we need more physical memory installed to
be able to boot a kernel.

Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/include/asm/page.h

@@ -117,14 +117,16 @@ extern int npmem_ranges;
 /* This governs the relationship between virtual and physical addresses.
  * If you alter it, make sure to take care of our various fixed mapping
  * segments in fixmap.h */
-#if defined(BOOTLOADER)
-#define __PAGE_OFFSET	(0)		/* bootloader uses physical addresses */
-#else
 #ifdef CONFIG_64BIT
-#define __PAGE_OFFSET	(0x40000000)	/* 1GB */
+#define __PAGE_OFFSET_DEFAULT	(0x40000000)	/* 1GB */
 #else
-#define __PAGE_OFFSET	(0x10000000)	/* 256MB */
+#define __PAGE_OFFSET_DEFAULT	(0x10000000)	/* 256MB */
 #endif
+
+#if defined(BOOTLOADER)
+#define __PAGE_OFFSET	(0)	/* bootloader uses physical addresses */
+#else
+#define __PAGE_OFFSET	__PAGE_OFFSET_DEFAULT
 #endif /* BOOTLOADER */
 
 #define PAGE_OFFSET		((unsigned long)__PAGE_OFFSET)