powerpc: Migrate SYS_L2_SIZE to Kconfig

Introduce two options, one for each observed L2 cache size, and have the
size select'd as needed.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/powerpc/cpu/mpc85xx/Kconfig b/arch/powerpc/cpu/mpc85xx/Kconfig
index 27f069a..7abfe26 100644
--- a/arch/powerpc/cpu/mpc85xx/Kconfig
+++ b/arch/powerpc/cpu/mpc85xx/Kconfig
@@ -113,6 +113,7 @@
 	select BOARD_LATE_INIT if CHAIN_OF_TRUST
 	select SUPPORT_SPL
 	select SUPPORT_TPL
+	select SYS_L2_SIZE_256KB
 	imply CMD_EEPROM
 	imply CMD_SATA
 	imply PANIC_HANG
@@ -123,6 +124,7 @@
 	select BOARD_LATE_INIT if CHAIN_OF_TRUST
 	select SUPPORT_SPL
 	select SUPPORT_TPL
+	select SYS_L2_SIZE_256KB
 	imply CMD_EEPROM
 	imply CMD_SATA
 	imply PANIC_HANG
@@ -132,6 +134,7 @@
 	select SUPPORT_SPL
 	select SUPPORT_TPL
 	select ARCH_P1020
+	select SYS_L2_SIZE_256KB
 	imply CMD_EEPROM
 	imply CMD_SATA
 	imply PANIC_HANG
@@ -141,6 +144,7 @@
 	select SUPPORT_SPL
 	select SUPPORT_TPL
 	select ARCH_P1020
+	select SYS_L2_SIZE_256KB
 	imply CMD_EEPROM
 	imply CMD_SATA
 	imply PANIC_HANG
@@ -150,6 +154,7 @@
 	select SUPPORT_SPL
 	select SUPPORT_TPL
 	select ARCH_P2020
+	select SYS_L2_SIZE_512KB
 	imply CMD_EEPROM
 	imply CMD_SATA
 	imply SATA_SIL
@@ -1277,6 +1282,17 @@
 	default 1
 endif
 
+config SYS_L2_SIZE_256KB
+	bool
+
+config SYS_L2_SIZE_512KB
+	bool
+
+config SYS_L2_SIZE
+	int
+	default 262144 if SYS_L2_SIZE_256KB
+	default 524288 if SYS_L2_SIZE_512KB
+
 config BACKSIDE_L2_CACHE
 	bool