[ARM] nommu: adjust headers for !MMU ARM systems

Majorily based on Hyok Choi's patches, this fixes up the asm-arm
header files for mmuless systems.  Over and above Hyok's patches:

- nommu.h merged into mmu.h (it's only a structure)
- nommu_context.h is essentially the same as mmu_context.h, but
  without the MM switching code.

so there's no point having separate files.  Also, in memory.h,
there's no point #ifndef'ing PHYS_OFFSET and END_MEM - both
CONFIG_DRAM_BASE and CONFIG_DRAM_SIZE will always be set by the
configuration scripts.

Other files have minor formatting changes, but are essentially
the same.  Hyok's original patches were signed off thusly:

  Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/include/asm-arm/domain.h b/include/asm-arm/domain.h
index f8ea2de..4c2885a 100644
--- a/include/asm-arm/domain.h
+++ b/include/asm-arm/domain.h
@@ -50,6 +50,8 @@
 #define domain_val(dom,type)	((type) << (2*(dom)))
 
 #ifndef __ASSEMBLY__
+
+#ifdef CONFIG_MMU
 #define set_domain(x)					\
 	do {						\
 	__asm__ __volatile__(				\
@@ -66,5 +68,10 @@
 	set_domain(thread->cpu_domain);				\
 	} while (0)
 
+#else
+#define set_domain(x)		do { } while (0)
+#define modify_domain(dom,type)	do { } while (0)
+#endif
+
 #endif
 #endif /* !__ASSEMBLY__ */