cpu/Kconfig: Remove MMX config option

Now -mno-mmx is statically set in arch/x86 so remove this option.

Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Change-Id: I0da7f9f1afb0c8ecae728c45591897ca1d4dfb11
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75318
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

src/cpu/intel/socket_441/Kconfig

@@ -6,7 +6,6 @@ if CPU_INTEL_SOCKET_441
 config SOCKET_SPECIFIC_OPTIONS
 	def_bool y
 	select CPU_INTEL_MODEL_106CX
-	select MMX
 	select SETUP_XIP_CACHE
 
 config DCACHE_RAM_BASE