ddr: altera: Replace float multiplication with integer one

ddr: altera: Replace float multiplication with integer one

This gem is really really rare, there was an actual float used in
the Altera DDR init code, which pulled in floating point ops from
the libgcc, just wow.

Since we don't support floating point operations the same way Linux
does not support them, replace this with an integer multiplication
and division combo. This removes some 2kiB of size from the SPL as
the floating point ops are no longer pulled in from libgcc.

This was detected by enabling CONFIG_USE_PRIVATE_LIBGCC=y , which
does not contain the floating point bits.

Signed-off-by: Marek Vasut <marex@denx.de>