clk: sunxi-ng: Fix round_rate/set_rate multiplier minimum mismatch

In commit 2beaa601 ("clk: sunxi-ng: Implement minimum for
multipliers"), the multiplier minimums in the set_rate callback
for NM and NKMP style clocks were not updated.

This patch fixes them to match their round_rate callbacks.

Fixes: 2beaa601 ("clk: sunxi-ng: Implement minimum for multipliers")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>