kbuild: rename LDFLAGS to KBUILD_LDFLAGS

Commit a0f97e06a43c ("kbuild: enable 'make CFLAGS=...' to add
additional options to CC") renamed CFLAGS to KBUILD_CFLAGS.

Commit 222d394d30e7 ("kbuild: enable 'make AFLAGS=...' to add
additional options to AS") renamed AFLAGS to KBUILD_AFLAGS.

Commit 06c5040cdb13 ("kbuild: enable 'make CPPFLAGS=...' to add
additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS.

For some reason, LDFLAGS was not renamed.

Using a well-known variable like LDFLAGS may result in accidental
override of the variable.

Kbuild generally uses KBUILD_ prefixed variables for the internally
appended options, so here is one more conversion to sanitize the
naming convention.

I did not touch Makefiles under tools/ since the tools build system
is a different world.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 8397c7b..11a1acb 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -76,14 +76,14 @@
 
 ifdef CONFIG_CPU_LITTLE_ENDIAN
 KBUILD_CFLAGS	+= -mlittle-endian
-LDFLAGS		+= -EL
+KBUILD_LDFLAGS	+= -EL
 LDEMULATION	:= lppc
 GNUTARGET	:= powerpcle
 MULTIPLEWORD	:= -mno-multiple
 KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-save-toc-indirect)
 else
 KBUILD_CFLAGS += $(call cc-option,-mbig-endian)
-LDFLAGS		+= -EB
+KBUILD_LDFLAGS	+= -EB
 LDEMULATION	:= ppc
 GNUTARGET	:= powerpc
 MULTIPLEWORD	:= -mmultiple
@@ -108,7 +108,7 @@
 ifeq ($(HAS_BIARCH),y)
 KBUILD_CFLAGS	+= -m$(BITS)
 KBUILD_AFLAGS	+= -m$(BITS) -Wl,-a$(BITS)
-LDFLAGS		+= -m elf$(BITS)$(LDEMULATION)
+KBUILD_LDFLAGS	+= -m elf$(BITS)$(LDEMULATION)
 KBUILD_ARFLAGS	+= --target=elf$(BITS)-$(GNUTARGET)
 endif