x86: Remove assembly versions of HAS_CPU_FEATURE/HAS_ARCH_FEATURE

Since all x86 IFUNC selectors are implemented in C, assembly versions of
HAS_CPU_FEATURE and HAS_ARCH_FEATURE can be removed.

	* sysdeps/x86/cpu-features.h [__ASSEMBLER__]
	(LOAD_RTLD_GLOBAL_RO_RDX, HAS_FEATURE, LOAD_FUNC_GOT_EAX,
	HAS_CPU_FEATURE, HAS_ARCH_FEATURE): Removed.