grub2: backport patch to fix CVE-2022-2601 CVE-2022-3775

grub2: backport patch to fix CVE-2022-2601 CVE-2022-3775

Backport patch from upstream to solve CVE-2022-2601 CVE-2022-3775 dependency:
font: Fix size overflow in grub_font_get_glyph_internal()
(https://git.savannah.gnu.org/cgit/grub.git/commit/?id=9c76ec09ae08155df27cd237eaea150b4f02f532)

Backport patch from upstream to fix following CVEs:
CVE-2022-2601: font: Fix several integer overflows in grub_font_construct_glyph()
(https://git.savannah.gnu.org/cgit/grub.git/commit/?id=768e1ef2fc159f6e14e7246e4be09363708ac39e)
CVE-2022-3775: font: Fix an integer underflow in blit_comb()
(https://git.savannah.gnu.org/cgit/grub.git/commit/?id=992c06191babc1e109caf40d6a07ec6fdef427af)

Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Liwei Song <liwei.song@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>