board: grouper: convert ASUS Google Nexus 7 (2012) to use DM PMIC

Since required drivers were merged, we can safely clean up the
board and switch to DM based driver with device tree support.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/board/asus/grouper/grouper-spl-max.c b/board/asus/grouper/grouper-spl-max.c
index 8443837..3e58bf9 100644
--- a/board/asus/grouper/grouper-spl-max.c
+++ b/board/asus/grouper/grouper-spl-max.c
@@ -9,7 +9,7 @@
  *  Svyatoslav Ryhel <clamor95@gmail.com>
  */
 
-#include <common.h>
+#include <asm/arch/tegra.h>
 #include <asm/arch-tegra/tegra_i2c.h>
 #include <linux/delay.h>