system: Add am335x-evm installer.

* gnu/system/install.scm (am335x-evm-installation-os):
  New exported variable.

Change-Id: I6dbe95f64d2c6f609fbf0e9c09e484f90850c70b
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>
Signed-off-by: Vagrant Cascadian <vagrant@debian.org>

gnu/system/install.scm

@@ -72,6 +72,7 @@
             a20-olinuxino-lime2-emmc-installation-os
             a20-olinuxino-micro-installation-os
             bananapi-m2-ultra-installation-os
+            am335x-evm-installation-os
             beaglebone-black-installation-os
             mx6cuboxi-installation-os
             nintendo-nes-classic-edition-installation-os
@@ -795,6 +796,14 @@ The bootloader BOOTLOADER is installed to BOOTLOADER-TARGET."
            (operating-system-user-kernel-arguments installation-os)))
     (initrd-modules (append extra-modules %base-initrd-modules))))
 
+(define am335x-evm-installation-os
+  (embedded-installation-os u-boot-am335x-evm-bootloader
+                            "/dev/sda"
+                            "ttyO0"
+                            #:extra-modules
+                            ;; This module is required to mount the sd card.
+                            '("omap_hsmmc")))
+
 (define beaglebone-black-installation-os
   (embedded-installation-os u-boot-beaglebone-black-bootloader
                             "/dev/sda"