ppc440_sdram: Get rid of the init RAM hack

ppc440_sdram: Get rid of the init RAM hack

Remove the do_init parameter of ppc440_sdram_init and enable SDRAM
controller from the board. Firmware does this so it may only be needed
when booting with -kernel without firmware but we enable SDRAM
unconditionally to preserve previous behaviour.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <c2eda8f83c82f655aa7821a5a8c9310484bd6a1d.1664021647.git.balaton@eik.bme.hu>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>