ARM: ICST: kill duplicate icst code

The only difference between ICST307 and ICST525 are the two arrays
for calculating the S parameter; the code is now identical.  Merge
the two files and kill the duplicated code.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/common/Kconfig b/arch/arm/common/Kconfig
index 4efbb9d..323d2d2 100644
--- a/arch/arm/common/Kconfig
+++ b/arch/arm/common/Kconfig
@@ -12,10 +12,7 @@
 	  The maximum number of VICs available in the system, for
 	  power management.
 
-config ICST525
-	bool
-
-config ICST307
+config ICST
 	bool
 
 config SA1111