kvm: add information on UEFI (#407)

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

Author: rohityadavcloud

source/installguide/hypervisor/kvm.rst

@@ -1479,12 +1479,17 @@ UEFI legacy / secureboot
 
 For deploying instances using UEFI legacy / secureboot, there are some further tasks to
 perform.
+
+In case of KVM, UEFI enabled hypervisor hosts must have the ``ovmf`` or
+``edk2-ovmf`` package installed.
+
 You can find further informations regarding prerequisites at the CloudStack Wiki
 (https://cwiki.apache.org/confluence/display/CLOUDSTACK/Enable+UEFI+booting+for+Instance)
 as well as limitations for using UEFI in CloudStack.
-The options to deploy a instances using UEFI can be found in the "Advanced Mode" section 
-of the instance deployment wizard.
 
+The options to deploy instances using UEFI can be found in the "Advanced Mode" section
+of the instance deployment wizard, where users can specify the boot type and
+boot mode for the selected valid template or ISO.
 
 Add the host to CloudStack
 ~~~~~~~~~~~~~~~~~~~~~~~~~~