powerpc: mpc85xx: Implemente workaround for CPU erratum A-007907

Core hang occurs when using L1 stashes. Workaround is to disable L1
stashes so software uses L2 cache for stashes instead.

Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Darwin Dingel <darwin.dingel@alliedtelesis.co.nz>
Cc: York Sun <york.sun@nxp.com>
[York S: Move SYS_FSL_ERRATUM_A007907 to Kconfig]
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/arch/powerpc/cpu/mpc85xx/Kconfig b/arch/powerpc/cpu/mpc85xx/Kconfig
index 704f65b..b0f34b6 100644
--- a/arch/powerpc/cpu/mpc85xx/Kconfig
+++ b/arch/powerpc/cpu/mpc85xx/Kconfig
@@ -365,6 +365,7 @@
 	select SYS_FSL_ERRATUM_A007075
 	select SYS_FSL_ERRATUM_A007186
 	select SYS_FSL_ERRATUM_A007212
+	select SYS_FSL_ERRATUM_A007907
 	select SYS_FSL_ERRATUM_A009942
 	select SYS_FSL_HAS_DDR3
 	select SYS_FSL_HAS_SEC
@@ -830,6 +831,7 @@
 	select SYS_FSL_ERRATUM_A006593
 	select SYS_FSL_ERRATUM_A007186
 	select SYS_FSL_ERRATUM_A007212
+	select SYS_FSL_ERRATUM_A007907
 	select SYS_FSL_ERRATUM_A009942
 	select SYS_FSL_ERRATUM_ESDHC111
 	select SYS_FSL_HAS_DDR3
@@ -891,6 +893,7 @@
 	select SYS_FSL_ERRATUM_A006593
 	select SYS_FSL_ERRATUM_A007186
 	select SYS_FSL_ERRATUM_A007798
+	select SYS_FSL_ERRATUM_A007907
 	select SYS_FSL_ERRATUM_A009942
 	select SYS_FSL_HAS_DDR3
 	select SYS_FSL_HAS_SEC
@@ -1081,6 +1084,9 @@
 config SYS_FSL_ERRATUM_A007798
 	bool
 
+config SYS_FSL_ERRATUM_A007907
+	bool
+
 config SYS_FSL_ERRATUM_A008044
 	bool