ARM: i.MX: esdctl: Introduce memory_sdram_size() ...

Introduce memory_sdram_size() - subroutine to calculate size of SDRAM
chip base on its parameters such as # or rows, columns, banks and bus
width.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

common: Add functions to find free RAM ...

The bootm code needs to put the Kernel image and initrd into free
RAM. Add some functions to find free RAM chunks to help this code.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

memory: return error in barebox_add_memory_bank ...

When a memory bank is already registered, return an error code
instead of throwing a bug. This can happen if a board has registered
a memory bank and the same bank is then probed from the devicetree.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

register sdram as resources ...

Also, request the sdram regions used by the barebox binary,
bss, malloc space and stack.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

introduce generic memory bank handling ...

On arm we have the concept of memory banks which can
be registered and iterated over. This is useful for
other architectures aswell, so add some generic infrastructure
for this.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

rename include/mem_malloc.h to include/memory.h ...

Which is a better name and also better to collect other
things.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>