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/Kconfig b/arch/arm/Kconfig
index 86fecec..3c436fd 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -240,7 +240,7 @@
 	select ARCH_HAS_CPUFREQ
 	select HAVE_CLK
 	select COMMON_CLKDEV
-	select ICST525
+	select ICST
 	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	help
@@ -251,7 +251,7 @@
 	select ARM_AMBA
 	select HAVE_CLK
 	select COMMON_CLKDEV
-	select ICST307
+	select ICST
 	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select ARCH_WANT_OPTIONAL_GPIOLIB
@@ -264,7 +264,7 @@
 	select ARM_VIC
 	select HAVE_CLK
 	select COMMON_CLKDEV
-	select ICST307
+	select ICST
 	select GENERIC_TIME
 	select GENERIC_CLOCKEVENTS
 	select ARCH_WANT_OPTIONAL_GPIOLIB