Kconfig and arch/Kconfig: Add some protection so that you cannot select an architecture-specific header file if the architecture does not provide the header file.

arch/Kconfig

@@ -14,6 +14,7 @@ config ARCH_ARM
 	select ARCH_HAVE_VFORK
 	select ARCH_HAVE_STACKCHECK
 	select ARCH_HAVE_CUSTOMOPT
+	select ARCH_HAVE_STDARG_H
 	---help---
 		The ARM architectures
 
@@ -43,6 +44,7 @@ config ARCH_MISOC
 	bool "MISOC"
 	select ARCH_HAVE_INTERRUPTSTACK
 	select ARCH_HAVE_CUSTOMOPT
+	select ARCH_HAVE_STDARG_H
 	---help---
 		MISOC
 
@@ -57,6 +59,7 @@ config ARCH_RISCV
 	bool "RISC-V"
 	select ARCH_HAVE_INTERRUPTSTACK
 	select ARCH_HAVE_CUSTOMOPT
+	select ARCH_HAVE_STDARG_H
 	---help---
 		RISC-V 32 and 64-bit RV32 / RV64 architectures.