microblaze: Move MSR instruction selection to Kconfig

Select MSR instructions via Kconfig instead of xparameters.h.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/microblaze-generic_defconfig b/configs/microblaze-generic_defconfig
index 7e53b5e..2ef713f 100644
--- a/configs/microblaze-generic_defconfig
+++ b/configs/microblaze-generic_defconfig
@@ -2,6 +2,7 @@
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_SPL_DM=y
 CONFIG_TARGET_MICROBLAZE_GENERIC=y
+CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR=1
 CONFIG_XILINX_MICROBLAZE0_USE_BARREL=1
 CONFIG_XILINX_MICROBLAZE0_USE_DIV=1
 CONFIG_XILINX_MICROBLAZE0_USE_HW_MUL=1