use lowercase directory name

package/uclibc/Makefile

@@ -2,7 +2,7 @@
 # material, please see the LICENCE file in the top-level directory.
 
 include $(TOPDIR)/rules.mk
-include $(TOPDIR)/toolchain/uClibc/Makefile.inc
+include $(TOPDIR)/toolchain/uclibc/Makefile.inc
 
 PKG_NAME:=		uClibc
 PKG_DESCR:=		embedded C library

toolchain/Makefile

@@ -21,8 +21,8 @@ TARGETS+=glibc
 LIBC:=glibc
 endif
 ifeq ($(ADK_TARGET_LIB_UCLIBC),y)
-TARGETS+=uClibc
-LIBC:=uClibc
+TARGETS+=uclibc
+LIBC:=uclibc
 endif
 ifeq ($(ADK_TARGET_LIB_MUSL),y)
 TARGETS+=musl