arch/x86: Populate more fields in SMBIOS type 4

If CPUID leaf 0x16 is available (Skylake and later) use it to obtain
current and maximum speed. Otherwise call weak function that can be
provided elsewhere (cpu/soc/mainboard). Also, populate "core enabled"
with the same value as "core count".

TEST=tested on OCP Monolake with dmidecode -t processor

Change-Id: Ie5d88dacae6623dfa0ceb3ca1bb5eeff2adda103
Signed-off-by: Andrey Petrov <anpetrov@fb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36283
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>

src/include/smbios.h

@@ -53,6 +53,9 @@ const char *smbios_system_version(void);
 void smbios_system_set_uuid(u8 *uuid);
 const char *smbios_system_sku(void);
 
+unsigned int smbios_cpu_get_max_speed_mhz(void);
+unsigned int smbios_cpu_get_current_speed_mhz(void);
+
 const char *smbios_mainboard_manufacturer(void);
 const char *smbios_mainboard_product_name(void);
 const char *smbios_mainboard_serial_number(void);