powerpc: Add LSDMR config values

powerpc: Add LSDMR config values

The LSDMR_* macros are used to configure the system bus on MPC83xx.

A few of the possible LSDMR_* macros were never defined in the
respective include files. This renders the SDRAM support on the
MPC8349EMDS unusable, because it uses these undefined macros.

To make the SDRAM option work, introduce these macros into the proper
config file.

Signed-off-by: Mario Six <mario.six@gdsys.cc>