microblaze: extable: sort the exception table at build time

Sort the exception table at build-time rather than during boot.

Microblaze is the same case as AARCH64 that's why EM_MICROBLAZE
conditional check was added to allow cross-compilation on machines which
are not running the latest libc-dev.

Inspired by AARCH64 commit adace895 ("arm64: extable: sort the
exception table at build time").
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: David Daney <david.daney@cavium.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/microblaze/Kconfig

@@ -30,6 +30,7 @@ config MICROBLAZE
 	select MODULES_USE_ELF_RELA
 	select CLONE_BACKWARDS3
 	select CLKSRC_OF
+	select BUILDTIME_EXTABLE_SORT
 
 config SWAP
 	def_bool n

scripts/sortextable.c

@@ -39,6 +39,10 @@
 #define EM_AARCH64	183
 #endif
 
+#ifndef EM_MICROBLAZE
+#define EM_MICROBLAZE	189
+#endif
+
 static int fd_map;	/* File descriptor for file being modified. */
 static int mmap_failed; /* Boolean flag. */
 static void *ehdr_curr; /* current ElfXX_Ehdr *  for resource cleanup */
@@ -275,6 +279,7 @@ do_file(char const *const fname)
 	case EM_ARCOMPACT:
 	case EM_ARM:
 	case EM_AARCH64:
+	case EM_MICROBLAZE:
 	case EM_MIPS:
 		break;
 	}  /* end switch */