remove lowercase symbols for C library

target/config/Config.in.libc.choice

@@ -6,7 +6,6 @@ prompt "C library"
 
 config ADK_TARGET_LIB_UCLIBC_NG
 	bool "uClibc-ng embedded C library"
-	select ADK_uclibc_ng
 	depends on \
 		   !ADK_TARGET_ARCH_AARCH64 && \
 		   !ADK_TARGET_ARCH_ALPHA && \
@@ -22,7 +21,6 @@ config ADK_TARGET_LIB_UCLIBC_NG
 
 config ADK_TARGET_LIB_MUSL
 	bool "musl C library"
-	select ADK_musl
 	depends on !ADK_TARGET_UCLINUX
 	depends on \
 		ADK_TARGET_ARCH_AARCH64 || \
@@ -38,7 +36,6 @@ config ADK_TARGET_LIB_MUSL
 
 config ADK_TARGET_LIB_GLIBC
 	bool "GNU C library"
-	select ADK_glibc
 	depends on !ADK_TARGET_ARCH_ARC
 	depends on !ADK_TARGET_ARCH_AVR32
 	depends on !ADK_TARGET_ARCH_BFIN
@@ -50,7 +47,6 @@ config ADK_TARGET_LIB_GLIBC
 
 config ADK_TARGET_LIB_UCLIBC
 	bool "uClibc embedded C library"
-	select ADK_uclibc
 	depends on ADK_BROKEN
 	depends on \
 		   !ADK_TARGET_ARCH_AARCH64 && \

target/config/Config.in.libc.default

@@ -1,18 +1,6 @@
 # This file is part of the OpenADK project. OpenADK is copyrighted
 # material, please see the LICENCE file in the top-level directory.
 
-config ADK_uclibc
-	bool
-
-config ADK_uclibc_ng
-	bool
-
-config ADK_glibc
-	bool
-
-config ADK_musl
-	bool
-
 config ADK_TARGET_WITH_LT
 	bool
 
@@ -21,10 +9,10 @@ config ADK_TARGET_WITH_NPTL
 
 config ADK_TARGET_LIBC
 	string
-	default "uclibc-ng"  if ADK_uclibc_ng
-	default "uclibc"  if ADK_uclibc
-	default "glibc"  if ADK_glibc
-	default "musl"  if ADK_musl
+	default "uclibc-ng" if ADK_TARGET_LIB_UCLIBC_NG
+	default "uclibc" if ADK_TARGET_LIB_UCLIBC
+	default "glibc" if ADK_TARGET_LIB_GLIBC
+	default "musl" if ADK_TARGET_LIB_MUSL
 
 config ADK_LIBC_VERSION
 	string