fs: Kill sh dependency for binfmt_flat.

Not really sure where this bogosity came from, but there's certainly
nothing special about sh that lets us use flat files with the MMU on.

Kill the dependency, and leave it as !MMU, like it is for all of the
other nommu-wielding ports.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

fs/Kconfig.binfmt

@@ -38,7 +38,7 @@ config BINFMT_ELF_FDPIC
 
 config BINFMT_FLAT
 	tristate "Kernel support for flat binaries"
-	depends on !MMU || SUPERH
+	depends on !MMU
 	help
 	  Support uClinux FLAT format binaries.