package/ipmitool: bump to version 1.8.19

- Switch to github to get latest release:
  https://sourceforge.net/projects/ipmitool/files/ipmitool/%21%21%21_READ_HERE_FIRST_%21%21%21
- Drop patches (already in version)

https://github.com/ipmitool/ipmitool/releases/tag/IPMITOOL_1_8_19



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>