power: pmic: add dm style definitions if not CONFIG_IS_ENABLED(POWER_LEGACY)

This avoids an error in converting to CONFIG_IS_ENABLED(DM_PMIC).
Many boards SPL code needs these definitions to compile, even if
the functions are not linked.

Signed-off-by: Troy Kisky <troykiskyboundary@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/power/pmic.h b/include/power/pmic.h
index 70f2709..6362216 100644
--- a/include/power/pmic.h
+++ b/include/power/pmic.h
@@ -86,7 +86,7 @@
 #endif /* CONFIG_IS_ENABLED(POWER_LEGACY) */
 
 /* TODO: Change to CONFIG_IS_ENABLED(DM_PMIC) when SPL_DM_PMIC exists */
-#ifdef CONFIG_DM_PMIC
+#if defined(CONFIG_DM_PMIC) || !CONFIG_IS_ENABLED(POWER_LEGACY)
 /**
  * U-Boot PMIC Framework
  * =====================