arm: mvebu: Remove dummy BIN header arguments for SPL binary

U-Boot SPL binary does not read BIN header arguments, so passing some dummy
values 0000005b and 00000068 has no effect for U-Boot SPL code.

Probably these two values comes from old Marvell DDR training code which
was separated from U-Boot and used it for some configuration.

Seems that two 32-bit values were specified here to ensure SPL code
alignment to 128-bit boundary as it is required e.g. for A370 or AXP
processors. Main kwbimage header is 64-byte long which is aligned to
128-bit boundary. Optional kwbheader is 32-bit long, number of BIN header
arguments is stored in 32-bit number. So for alignment to 128-bit boundary
is needed 64-bit padding which exactly these two 32-bit dummy arguments
provided.

Now when mkimage correctly aligns start of executable code in BIN header to
128-bit boundary, there is no requirement to put dummy argument values into
kwbimage. So remove them.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>