dell-wmi: support Dell Inspiron M5110

Similarly to Dell Vostro V131, Dell Inspiron M5110 also requires an
SMBIOS request to be issued in order for WMI events to be generated and
does not raise an i8042 interrupt when the Dell Instant Launch hotkey is
pressed.  However, the event code for that hotkey on this machine is
0xe029, so add it to the legacy keymap.

Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Tested-by: Darek Stojaczyk <darek.stojaczyk@gmail.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>