change HAS_FPU to UCLIBC_HAS_FPU since the define will be exported into C namespace

extra/Configs/Config.in.arch

@@ -48,7 +48,7 @@ config UCLIBC_HAS_FLOATS
 	  Answering N to this option can reduce the size of uClibc.  Most people
 	  will answer Y.
 
-config HAS_FPU
+config UCLIBC_HAS_FPU
 	bool "Target CPU has a floating point unit (FPU)"
 	depends on UCLIBC_HAS_FLOATS
 	default y
@@ -64,7 +64,7 @@ config HAS_FPU
 
 config UCLIBC_HAS_SOFT_FLOAT
 	bool
-	depends on UCLIBC_HAS_FLOATS && !HAS_FPU
+	depends on UCLIBC_HAS_FLOATS && !UCLIBC_HAS_FPU
 	default y
 
 config DO_C99_MATH

libm/Makefile.in

@@ -33,7 +33,7 @@ LIBS-libm.so := $(LIBS)
 
 libm_FULL_NAME := libm-$(MAJOR_VERSION).$(MINOR_VERSION).$(SUBLEVEL).so
 
-ifeq ($(HAS_FPU),y)
+ifeq ($(UCLIBC_HAS_FPU),y)
 -include $(top_srcdir)libm/$(TARGET_ARCH)/Makefile.arch
 endif
 
@@ -84,7 +84,7 @@ libm_DIR := $(top_srcdir)libm
 libm_OUT := $(top_builddir)libm
 
 # assume that arch specific versions are provided as single sources/objects
-ifeq ($(HAS_FPU),y)
+ifeq ($(UCLIBC_HAS_FPU),y)
 ifneq ($(strip $(libm_ARCH_OBJS)),)
 
 # remove generic sources, if arch specific version is present