Drivers: hv: vmbus: Move the check for hypercall page setup

As part of the effort to separate out architecture specific code, move the
check for detecting if the hypercall page is setup.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/x86/include/asm/mshyperv.h

@@ -115,5 +115,6 @@ void hv_remove_crash_handler(void);
 #if IS_ENABLED(CONFIG_HYPERV)
 void hyperv_init(void);
 void hyperv_report_panic(struct pt_regs *regs);
+bool hv_is_hypercall_page_setup(void);
 #endif
 #endif