fix: Fix mrf.spec.in for RPM package

Remove no needed tools, and set arch as noarch, considering the dkms
builds the kernel module on the host where the package is to be
installed.

mrmShared/linux/dkms-rpm/mrf.spec.in

@@ -13,8 +13,7 @@ Vendor: EPICS Community
 License: GPLv2
 Group: System Environment/Kernel
 URL: https://github.com/epics-modules/mrfioc2
-BuildRequires: autoconf libtool gcc gcc-c++
-BuildArch: @@ARCH@@
+BuildArch: noarch
 Requires: dkms
 Requires: udev
 BuildRoot: %{_tmppath}/%{kmod_name}-%{version}-root