sh: Only support PMB for SH-X cores.

We don't have a PMB for SH-X2 or later, so only enable it for
the few CPUs that support it. Fixes up the boot for SH4AL-DSP.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/mm/Kconfig

@@ -263,7 +263,7 @@ config MEMORY_SIZE
 
 config 32BIT
 	bool "Support 32-bit physical addressing through PMB"
-	depends on CPU_SH4A && MMU && (!X2TLB || BROKEN)
+	depends on MMU && (CPU_SUBTYPE_SH7780 || CPU_SUBTYPE_SH7785)
 	default y
 	help
 	  If you say Y here, physical addressing will be extended to