southbridge/amd/sr5650/sr5650.c: Fix bitwise logic and mask in loop

Correct mask to select bits 4-6 inclusively as per comment and use
bitwise operations while working with bits. Be sure to write back out
the data on the retrain.

See:
 commit cab9efb2 southbridge/amd/rsXY0/cmn.c: Fix bitwise logic and mask in loop

Change-Id: I95d1799514157b7849f3e473837aaf2fd9bd59b9
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/7692
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Tested-by: build bot (Jenkins)
mainboard/siemens/sitemp_g1p1/mainboard.c: Fix implicit conversion

Clang warns of an implicit conversion from 'double' to 'int'
e.g. changes value from '26.67' to '26'. Thus take the floor() of
the array and not change orginal behaviour.

Change-Id: Ifcc7bbfe8d627451b82053f53a885f315e2550ec
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/7725
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Tested-by: build bot (Jenkins)