board/qemu/sh4-r2d: fix sh4 kernel bug with binutils 2.33

board/qemu/sh4-r2d: fix sh4 kernel bug with binutils 2.33

Remove the binutils patch reverting [1] that triggers a sh4 kernel bug
with binutils >= 2.33. Instead, add two kernel patches provided by
Alan Modra [2] that fix alignment of rodata.

[1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ebd2263ba9a9124d93bbc0ece63d7e0fae89b40e
[2] https://www.sourceware.org/ml/binutils/2019-12/msg00112.html

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>