powerpc/pseries/htmdump: Include header file to get is_kvm_guest() definition

htmdump_init calls is_kvm_guest() to check for guest environment.
is_kvm_guest() is defined in kvm_guest.h header file. Without including
the header file, build hits error failing to find the function.

  arch/powerpc/platforms/pseries/htmdump.c: In function 'htmdump_init':
  arch/powerpc/platforms/pseries/htmdump.c:469:6: error: implicit declaration of function 'is_kvm_guest';
  did you mean '__key_get'? [-Werror=implicit-function-declaration]
  if (is_kvm_guest()) {
      ^~~~~~~~~~~~
      __key_get

This is observed in configs where CONFIG_KVM_GUEST is disabled.
Include header file explicitly to avoid the build error

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Athira Rajeev <[email protected]>
Tested-by: Venkat Rao Bagalkote <[email protected]>
Signed-off-by: Madhavan Srinivasan <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: Athira Rajeev

arch/powerpc/platforms/pseries/htmdump.c

@@ -10,6 +10,7 @@
 #include <asm/io.h>
 #include <asm/machdep.h>
 #include <asm/plpar_wrappers.h>
+#include <asm/kvm_guest.h>
 
 static void *htm_buf;
 static void *htm_status_buf;