ARM: s5p64x0_defconfig: Update for support S5P6440 and S5P6450

This patch updates s5p64x0_defconfig and changes the name from
s5p6440_defconfig so that can support S5P6440 and S5P6450 with
one kernel.

Tested on SMDK6440(S5P6440) and SMDK6450(S5P6450).
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/configs/s5p6440_defconfig → arch/arm/configs/s5p64x0_defconfig

@@ -5,10 +5,11 @@ CONFIG_KALLSYMS_ALL=y
 CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
 # CONFIG_BLK_DEV_BSG is not set
-CONFIG_ARCH_S5P6440=y
+CONFIG_ARCH_S5P64X0=y
 CONFIG_S3C_BOOT_ERROR_RESET=y
 CONFIG_S3C_LOWLEVEL_UART_PORT=1
 CONFIG_MACH_SMDK6440=y
+CONFIG_MACH_SMDK6450=y
 CONFIG_CPU_32v6K=y
 CONFIG_AEABI=y
 CONFIG_CMDLINE="root=/dev/ram0 rw ramdisk=8192 initrd=0x20800000,8M console=ttySAC1,115200 init=/linuxrc"