main/postmarketos-base: depend on openssh-server-pam (MR 6244)

Always make sure openssh server w/ PAM support is installed. This also
drops an implicit dependency on `openssh-client`, this was pulled in
previously by `depends="openssh"`.

fixes #3570

main/postmarketos-base/APKBUILD

 pkgname=postmarketos-base
 pkgver=42
-pkgrel=0
+pkgrel=1
 pkgdesc="Meta package for minimal postmarketOS base"
 url="https://postmarketos.org"
 arch="noarch"
@@ -10,7 +10,7 @@ depends="
 	alpine-base
 	devicepkg-utils>=0.2.0
 	eudev
-	openssh
+	openssh-server-pam
 	postmarketos-bootsplash
 	postmarketos-ramdisk
 	postmarketos-mvcfg