ls1021a: adding a secondary core boot address and kick functions

ls1021a: adding a secondary core boot address and kick functions

Define the board specific smp_set_cpu_boot_addr() function to set
the start address for secondary cores in the LS1021A specific manner.

Define the board specific smp_kick_all_cpus() functioin to boot a
secondary core. Here the BRR contains control bits for enabling boot
for each core. On exiting HRESET or PORESET, the RCW BOOT_HO field
optionally allows for logical core 0 to be released for booting or to
remain in boot holdoff. All other cores remain in boot holdoff until
their corresponding bit is set.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>