[MIPS] IP32: Remove experimental tag from kconfig.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -433,8 +433,7 @@ config SGI_IP27
 	  here.
 
 config SGI_IP32
-	bool "SGI IP32 (O2) (EXPERIMENTAL)"
-	depends on EXPERIMENTAL
+	bool "SGI IP32 (O2)"
 	select ARC
 	select ARC32
 	select BOOT_ELF32