meson: Remove autotools support and update READMEs

Tested: Ran CI.

Change-Id: Ie1327e27e07c0304ceb7c3fcfad4bc8f1b18b89c
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/.gitignore b/.gitignore
index 602baba..378eac2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,52 +1 @@
-# Template from:
-# https://github.com/github/gitignore/blob/master/Autotools.gitignore
-
-# http://www.gnu.org/software/automake
-
-Makefile.in
-/ar-lib
-/mdate-sh
-/py-compile
-/test-driver
-/ylwrap
-
-# http://www.gnu.org/software/autoconf
-
-/autom4te.cache
-/aclocal.m4
-/compile
-/config.guess
-/config.h.in
-/config.sub
-/configure
-/configure.scan
-/depcomp
-/install-sh
-/missing
-/stamp-h1
-
-# https://www.gnu.org/software/libtool/
-
-/ltmain.sh
-
-# http://www.gnu.org/software/texinfo
-
-/texinfo.tex
-
-# Repo Specific Items
-*.o
-*.trs
-/config.h
-/config.h.in~
-*.log
-/config.status
-/openpower-update-manager
-Makefile
-.deps
-*-libtool
-/test/utest
-/m4/*.m4
-/openpower-pnor-msl
-/org/openbmc/Associations/
-.dirstamp
-
+build