LoongArch: KVM: Move some variable declarations to paravirt.h

Some variables relative with paravirt feature are declared in the header
file asm/qspinlock.h, however this file can be included only when option
CONFIG_SMP is on. There is compiling warnings if CONFIG_SMP is off since
variables are not declared.

Move these variable declarations to header file asm/paravirt.h to avoid
compiling warnings.

Fixes: c43dce6f13 ("LoongArch: KVM: Make vcpu_is_preempted() as a macro rather than function")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202605061313.O8Hswm2b-lkp@intel.com/
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

arch/loongarch/include/asm/paravirt.h

@@ -4,6 +4,12 @@
 
 #ifdef CONFIG_PARAVIRT
 
+#include <linux/jump_label.h>
+
+DECLARE_STATIC_KEY_FALSE(virt_preempt_key);
+DECLARE_STATIC_KEY_FALSE(virt_spin_lock_key);
+DECLARE_PER_CPU(struct kvm_steal_time, steal_time);
+
 int __init pv_ipi_init(void);
 int __init pv_time_init(void);
 int __init pv_spinlock_init(void);

arch/loongarch/include/asm/qspinlock.h

@@ -3,12 +3,9 @@
 #define _ASM_LOONGARCH_QSPINLOCK_H
 
 #include <asm/kvm_para.h>
-#include <linux/jump_label.h>
+#include <asm/paravirt.h>
 
 #ifdef CONFIG_PARAVIRT
-DECLARE_STATIC_KEY_FALSE(virt_preempt_key);
-DECLARE_STATIC_KEY_FALSE(virt_spin_lock_key);
-DECLARE_PER_CPU(struct kvm_steal_time, steal_time);
 
 #define virt_spin_lock virt_spin_lock