Revert "x86/hyper-v: include hyperv/ only when CONFIG_HYPERV is set"

This reverts commit 2e252fbf777d3b1250b63a5bf45e2ac1932687d3 as it is
obviously not correct.

And it should have gone in through the x86 tree :(

Reported-by: Colin King <colin.king@canonical.com>
Reported-by: Ingo Molnar <mingo@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/x86/Kbuild

@@ -8,7 +8,7 @@ obj-$(CONFIG_KVM) += kvm/
 obj-$(CONFIG_XEN) += xen/
 
 # Hyper-V paravirtualization support
-obj-$(subst m,y,$(CONFIG_HYPERV)) += hyperv/
+obj-$(CONFIG_HYPERVISOR_GUEST) += hyperv/
 
 # lguest paravirtualization support
 obj-$(CONFIG_LGUEST_GUEST) += lguest/

arch/x86/include/asm/mshyperv.h

@@ -175,12 +175,7 @@ void hyperv_init(void);
 void hyperv_report_panic(struct pt_regs *regs);
 bool hv_is_hypercall_page_setup(void);
 void hyperv_cleanup(void);
-#else /* CONFIG_HYPERV */
-static inline void hyperv_init(void) {}
-static inline bool hv_is_hypercall_page_setup(void) { return false; }
-static inline hyperv_cleanup(void) {}
-#endif /* CONFIG_HYPERV */
-
+#endif
 #ifdef CONFIG_HYPERV_TSCPAGE
 struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
 static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)