Update ipxe to a more recent version

This is a tentative to make ipxe more close to the current version
and include some improvements and bug fixes.
Also improves compatibility with recent gcc and build libraries.

Signed-off-by: Riccardo Pittau <elfosardo@gmail.com>

Dockerfile

@@ -10,8 +10,10 @@ RUN dnf install -y gcc git make xz-devel
 
 WORKDIR /tmp
 
-RUN git clone --depth 1 --branch v1.21.1 https://github.com/ipxe/ipxe.git && \
-      cd ipxe/src && \
+RUN git clone https://github.com/ipxe/ipxe.git && \
+      cd ipxe && \
+      git reset --hard 9062544f6a0c69c249b90d21a08d05518aafc2ec && \
+      cd src && \
       ARCH=$(uname -m | sed 's/aarch/arm/') && \
       # NOTE(elfosardo): warning should not be treated as errors by default
       NO_WERROR=1 make bin/undionly.kpxe "bin-$ARCH-efi/snponly.efi"