powerpc: Migrate HIGH_BATS to Kconfig

Migrate the CONFIG_HIGH_BATS variable to Kconfig.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/configs/MPC837XEMDS_defconfig b/configs/MPC837XEMDS_defconfig
index da908c7..cf0694f 100644
--- a/configs/MPC837XEMDS_defconfig
+++ b/configs/MPC837XEMDS_defconfig
@@ -2,6 +2,7 @@
 CONFIG_SYS_TEXT_BASE=0xFE000000
 CONFIG_SYS_CLK_FREQ=66000000
 CONFIG_MPC83xx=y
+CONFIG_HIGH_BATS=y
 CONFIG_TARGET_MPC837XEMDS=y
 CONFIG_DDR_MC_CLOCK_MODE_1_1=y
 CONFIG_SYSTEM_PLL_FACTOR_6_1=y