package/mmc-utils: bump to latest commit

The changes are:

d0b4644 mmc-utils: add ability to enable/disable optional eMMC cache
64c2de8 mmc-utils: Add command to set the boot bus conditions
7891236 mmc-utils: add support to create gp partition
4afc8c8 mmc-utils: add check for max enhanced user area
50b6854 fix building errors on Android
f4eb241 Fit usage to 80 cols
c6cb053 mmc-utils: RPMB: add support for 4 rpmb operations
35c31fe mmc-utils: RPMB: add HMAC SHA256 support
a8276f5 fix make handling

Signed-off-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>