ARM: KVM: Teach some form of type-safety to kvm_call_hyp

Just like on arm64, and for the same reasons, kvm_call_hyp removes
any form of type safety when calling into HYP. But we can still
try to tell the compiler what we're trying to achieve.

Here, we can add code that would do the function call if it wasn't
guarded by an always-false predicate. Hopefully, the compiler is
dumb enough to do the type checking and clever enough to not emit
the corresponding code...

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>

arch/arm/kvm/hyp/hyp-entry.S

@@ -176,7 +176,7 @@ THUMB(	orr	lr, lr, #PSR_T_BIT	)
 	msr	spsr_cxsf, lr
 	ldr	lr, =panic
 	msr	ELR_hyp, lr
-	ldr	lr, =kvm_call_hyp
+	ldr	lr, =__kvm_call_hyp
 	clrex
 	eret
 ENDPROC(__hyp_do_panic)

arch/arm/kvm/interrupts.S

@@ -42,7 +42,7 @@
  *   r12:     caller save
  *   rest:    callee save
  */
-ENTRY(kvm_call_hyp)
+ENTRY(__kvm_call_hyp)
 	hvc	#0
 	bx	lr
-ENDPROC(kvm_call_hyp)
+ENDPROC(__kvm_call_hyp)