mpc83xx: Migrate CONFIG_SYS_{BR, OR}*_PRELIM to Kconfig

Migrate the BR/OR settings to Kconfig. These must be known at compile
time, so cannot be configured via DT.

Configuration of this crucial variable should still be somewhat
comfortable. Hence, make its fields configurable in Kconfig, and
assemble the final value from these.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
diff --git a/configs/sbc8349_defconfig b/configs/sbc8349_defconfig
index 05361f7..4ec51af 100644
--- a/configs/sbc8349_defconfig
+++ b/configs/sbc8349_defconfig
@@ -67,3 +67,17 @@
 # CONFIG_PCI is not set
 CONFIG_SYS_NS16550=y
 CONFIG_OF_LIBFDT=y
+CONFIG_ELBC_BR0_OR0=y
+CONFIG_BR0_OR0_NAME="FLASH"
+CONFIG_BR0_OR0_BASE=0xFF800000
+CONFIG_BR0_MACHINE_GPCM=y
+CONFIG_BR0_PORTSIZE_16BIT=y
+CONFIG_OR0_AM_8_MBYTES=y
+CONFIG_OR0_ACS_HALF_CYCLE_EARLIER=y
+CONFIG_OR0_CSNT_EARLIER=y
+CONFIG_OR0_EAD_EXTRA=y
+CONFIG_OR0_SCY_15=y
+CONFIG_OR0_XACS_EXTENDED=y
+CONFIG_OR0_XAM_SET=y
+CONFIG_OR0_TRLX_RELAXED=y
+CONFIG_OR0_EHTR_8_CYCLE=y