fix the following 'make includecheck' warning:

  arch/arm/mach-davinci/board-sffsdr.c: mach/common.h is included more than once.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Acked-by: Philip Balister <philip@opensdr.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>