arm64: KVM: remove __kvm_hyp_code_{start,end} from hyp.S

We already have __hyp_text_{start,end} to express the boundaries
of the HYP text section, and __kvm_hyp_code_{start,end} are getting
in the way of a more modular world switch code.

Just turn __kvm_hyp_code_{start,end} into #defines mapping the
linker-emited symbols.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

arch/arm64/include/asm/virt.h

@@ -50,6 +50,10 @@ static inline bool is_hyp_mode_mismatched(void)
 	return __boot_cpu_mode[0] != __boot_cpu_mode[1];
 }
 
+/* The section containing the hypervisor text */
+extern char __hyp_text_start[];
+extern char __hyp_text_end[];
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* ! __ASM__VIRT_H */