linux-user: Add some new blk ioctls

Add some new blk ioctls (these are 0x12,119 through
to 0x12,127). Several of these are used by mke2fs; this silences
the warnings:

mke2fs 1.42.12 (29-Aug-2014)
Unsupported ioctl: cmd=0x127b
Unsupported ioctl: cmd=0x127a
warning: Unable to get device geometry for /dev/loop5
Unsupported ioctl: cmd=0x127c
Unsupported ioctl: cmd=0x127c
Unsupported ioctl: cmd=0x1277

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
