Commit 1b673ef breaks riotboard boot

[Nikolay Dimitrov <picmaster@mail.bg>]

Hi Fabio,

Commit 1b673ef (linux-fslc, branch "patch-4.0") breaks booting of
riotboard. Reverting the patch allows the board to boot properly. It
looks like the patch causes some issue with the sdcard detection, as
shown below in the logs (only the emmc is detected):

[    1.447707] sdhci: Secure Digital Host Controller Interface driver
[    1.453974] sdhci: Copyright(c) Pierre Ossman
[    1.458488] sdhci-pltfm: SDHCI platform and OF driver helper
[    1.465423] sdhci-esdhc-imx 2194000.usdhc: could not get ultra high 
speed state, work on normal mode
[    1.474725] sdhci-esdhc-imx 2194000.usdhc: Got CD GPIO
[    1.479985] sdhci-esdhc-imx 2194000.usdhc: Got WP GPIO
[    1.485574] sdhci-esdhc-imx 2194000.usdhc: No vqmmc regulator found
[    1.539993] mmc0: SDHCI controller on 2194000.usdhc [2194000.usdhc] 
using ADMA
[    1.551185] sdhci-esdhc-imx 2198000.usdhc: could not get ultra high 
speed state, work on normal mode
[    1.574222] sdhci-esdhc-imx 2198000.usdhc: Got CD GPIO
[    1.589766] sdhci-esdhc-imx 2198000.usdhc: Got WP GPIO
[    1.606144] sdhci-esdhc-imx 2198000.usdhc: No vqmmc regulator found
...
[    2.408926] VFS: Cannot open root device "mmcblk0p2" or 
unknown-block(179,2): error -6
[    2.416860] Please append a correct "root=" boot option; here are the 
available partitions:
...
[    2.500580] b300         3751936 mmcblk0  driver: mmcblk
[    2.505927] b318             128 mmcblk0rpmb  (driver?)
[    2.511211] b310            2048 mmcblk0boot1  (driver?)
[    2.516554] b308            2048 mmcblk0boot0  (driver?)
[    2.522003] Kernel panic - not syncing: VFS: Unable to mount root fs 
on unknown-block(179,2)
[    2.530452] drm_kms_helper: panic occurred, switching back to text 
console
[    2.537649] ---[ end Kernel panic - not syncing: VFS: Unable to mount 
root fs on unknown-block(179,2)

Thanks in advance for looking into this. Regards,
Nikolay