ddr: fsl: fix a compile issue

When CONFIG_SYS_FSL_ERRATUM_A009801 is defined but
CONFIG_SYS_FSL_ERRATUM_A008511 not defined, there is compile error
that temp32 undeclared, this patch fixes it.

Signed-off-by: Shaohui Xie <Shaohui.Xie@nxp.com>
Signed-off-by: Gong Qianyu <Qianyu.Gong@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>