ARM: UniPhier: merge UniPhier config headers into a single file

Some configurations have been moved to Kconfig and the difference
among the config headers of UniPhier SoC variants is getting smaller
and smaller.  Now is a good time to merge them into a single file.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
diff --git a/arch/arm/cpu/armv7/uniphier/Kconfig b/arch/arm/cpu/armv7/uniphier/Kconfig
index 1d96db2..9760299 100644
--- a/arch/arm/cpu/armv7/uniphier/Kconfig
+++ b/arch/arm/cpu/armv7/uniphier/Kconfig
@@ -5,9 +5,7 @@
 	default "uniphier"
 
 config SYS_CONFIG_NAME
-	default "ph1_pro4" if MACH_PH1_PRO4
-	default "ph1_ld4" if MACH_PH1_LD4
-	default "ph1_sld8" if MACH_PH1_SLD8
+	default "uniphier"
 
 config UNIPHIER_SMP
 	bool