ColdFire: Fix alignment issue after CONFIG_IDENT_STRING in start.S

ColdFire: Fix alignment issue after CONFIG_IDENT_STRING in start.S

When the version_string function in start.S is not 4-byte align,
it will cause the compiler generates "unaligned opcodes detected
in executable segment". This issue affects all ColdFire CPUs.
By adding .align 4 after CONFIG_IDENT_STRING, it will pad 0's if
it is not aligned.

Signed-off-by: TsiChung Liew <Tsi-Chung.Liew@freescale.com>
Acked-by: John Rigby <jrigby@freescale.com>