mmc: sdhci: fix ctrl_2 on super-speed selection

This patch fixes the HC ctrl_2 programming where, in case of
SDR104 and HS200, we have to write 100b in the the UHS Mode
bits. We wrote 101b that is reserved from Arasan Specs.

Reported-by: Youssef Triki <youssef.triki@st.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Chris Ball <cjb@laptop.org>