hdparm: Fix LDFLAGS

Based on debian patch. LDFLAGS were not being passed, which caused relro
to not be applies.

Also made stock CFLAGS optional. -fkeep-inline was keeping sizes high.

Removed PKG_NO_MIPS16 as the original problem seems to be gone.

Size from 54338 to 50761

Signed-off-by: Rosen Penev <rosenp@gmail.com>

utils/hdparm/Makefile

@@ -10,7 +10,6 @@ include $(TOPDIR)/rules.mk
 PKG_NAME:=hdparm
 PKG_VERSION:=9.58
 PKG_RELEASE:=1
-PKG_USE_MIPS16:=0
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=@SF/$(PKG_NAME)
@@ -21,8 +20,6 @@ PKG_LICENSE:=BSD-Style Open Source License
 
 include $(INCLUDE_DIR)/package.mk
 
-TARGET_CFLAGS+=-D_GNU_SOURCE
-
 define Package/hdparm
   SECTION:=utils
   CATEGORY:=Utilities