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/kmtepr2_defconfig b/configs/kmtepr2_defconfig
index ed8bc32..0f32283 100644
--- a/configs/kmtepr2_defconfig
+++ b/configs/kmtepr2_defconfig
@@ -2,6 +2,7 @@
 CONFIG_SYS_TEXT_BASE=0xF0000000
 CONFIG_SYS_CLK_FREQ=66000000
 CONFIG_MPC83xx=y
+CONFIG_HIGH_BATS=y
 CONFIG_TARGET_KMTEPR2=y
 CONFIG_CORE_PLL_RATIO_25_1=y
 CONFIG_QUICC_MULT_FACTOR_3=y