FROMGIT: mmc: debugfs: Add debug fs entry for mmc driver

Add debug fs entry to query eMMC and SD card errors statistics

(cherry picked from commit 1cb1c0757911aa2ca35593e319dc06daa7395c2d
 https://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc.git devel)
Bug: 233007144
Link: https://lore.kernel.org/lkml/1652857340-6040-4-git-send-email-quic_c_sbhanu@quicinc.com/



Signed-off-by: Liangliang Lu <quic_luliang@quicinc.com>
Signed-off-by: Sayali Lokhande <quic_sayalil@quicinc.com>
Signed-off-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>
Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
Change-Id: I38d33b9faa868ef7d9bc32d0d91cda8d2dd0cca6