cpu/qemu-x86: Add an option to use the smmloader v2

The idea is to get rid of having 2 different smmloaders so add this
option only to qemu/q35 to get it buildtested.

Change-Id: Id4901784c4044e945b7f258b3acdc8d549665f3a
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51525
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

configs/config.emulation_qemu_x86_q35_smm_tseg

@@ -0,0 +1,4 @@
+CONFIG_BOARD_EMULATION_QEMU_X86_Q35=y
+CONFIG_CPU_QEMU_X86_PARALLEL_MP=y
+CONFIG_CPU_QEMU_X86_TSEG_SMM=y
+CONFIG_CPU_QEMU_X86_SMMLOADERV2=y

src/cpu/qemu-x86/Kconfig

@@ -43,6 +43,20 @@ config CPU_QEMU_X86_TSEG_SMM
 
 endchoice
 
+choice
+	prompt "SMM loader"
+	default CPU_QEMU_X86_SMMLOADERV1
+	depends on SMM_TSEG
+
+config CPU_QEMU_X86_SMMLOADERV1
+	bool "smmloader v1"
+
+config CPU_QEMU_X86_SMMLOADERV2
+	bool "smmloader v2"
+	select X86_SMM_LOADER_VERSION2
+
+endchoice
+
 config MAX_CPUS
 	int
 	default 32 if SMM_TSEG