arm: Add Kconfig entry for MACH_TYPE

As part of migrating support for ATAGs to Kconfig, add an option for
setting and passing MACH_TYPE.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/nokia_rx51_defconfig b/configs/nokia_rx51_defconfig
index e6e8f2a..69784d9 100644
--- a/configs/nokia_rx51_defconfig
+++ b/configs/nokia_rx51_defconfig
@@ -6,6 +6,8 @@
 CONFIG_CMDLINE_TAG=y
 CONFIG_INITRD_TAG=y
 CONFIG_REVISION_TAG=y
+CONFIG_STATIC_MACH_TYPE=y
+CONFIG_MACH_TYPE=1955
 CONFIG_SYS_TEXT_BASE=0x80008000
 CONFIG_NR_DRAM_BANKS=2
 CONFIG_SYS_MALLOC_LEN=0xc0000