sh: Add SH7720 CPU support.

This adds support for the SH7720 (SH3-DSP) CPU.

Signed-off by: Markus Brunner <super.firetwister@gmail.com>
Signed-off by: Mark Jonas <toertel@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/mm/Kconfig b/arch/sh/mm/Kconfig
index e5801d9..5487b99 100644
--- a/arch/sh/mm/Kconfig
+++ b/arch/sh/mm/Kconfig
@@ -111,6 +111,14 @@
 	help
 	  Select SH7712 if you have a SH3-DSP SH7712 CPU.
 
+config CPU_SUBTYPE_SH7720
+	bool "Support SH7720 processor"
+	select CPU_SH3
+	select CPU_HAS_INTC_IRQ
+	select CPU_HAS_DSP
+	help
+	  Select SH7720 if you have a SH3-DSP SH7720 CPU.
+
 # SH-4 Processor Support
 
 config CPU_SUBTYPE_SH7750