Rename CONFIG_SYS_INIT_RAM_END into CONFIG_SYS_INIT_RAM_SIZE

CONFIG_SYS_INIT_RAM_END was a misnomer as it suggests this might be
some end address; to make the meaning more clear we rename it into
CONFIG_SYS_INIT_RAM_SIZE

No other code changes are performed in this patch, only minor editing
of white space (due to the changed length) and the comments was done,
where noticed.

Note that the code for the PATI and cmi_mpc5xx board configurations
looks seriously broken.  Last known maintainers on Cc:

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Denis Peter <d.peter@mpl.ch>
Cc: Martin Winistoerfer <martinwinistoerfer@gmx.ch>
Acked-by: Kumar Gala <galak@kernel.crashing.org>