Fix: Update mkinitcpio command to use -P option

use ```mkinitcpio -P``` instead of hardcoded ```mkintcpio -p linux``` 
(fix suggested by cube and validated by copilot)
(manpage for mkinitcpio says
```-P, --allpresets
         Process all presets contained in /etc/mkinitcpio.d. See the -p option for more detail about presets.
-p, --preset preset
         Build initramfs image(s) according to specified preset. This  may  be  a  file  in  /etc/mkinitcpio.d
         (without the .preset extension) or a full, absolute path to a file. This option may be specified mul‐
         tiple times to process multiple presets.```
This does seem to remove hard coded path

quickemu

@@ -30,8 +30,8 @@ function ignore_msrs_always() {
 		            sudo update-initramfs -k all -u
 		            ;;
 	            2)
-		            sudo mkinitcpio -p linux
-                echo "Ran mkinitcpio -p linux"
+		            sudo mkinitcpio -P
+                echo "Ran mkinitcpio -P"
 		            ;;
 	            3)
 		            echo "ERROR! User does not have update-initramfs or mkinitcpio installed, please find out respective utility to update/regenrate intiramfs."