grub: Fix multiple CVEs

grub: Fix multiple CVEs

Backport fixes for:

* CVE-2024-45774 - Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=2c34af908ebf4856051ed29e46d88abd2b20387f
* CVE-2024-45775 - Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=05be856a8c3aae41f5df90cab7796ab7ee34b872
* CVE-2024-45776 - Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=09bd6eb58b0f71ec273916070fa1e2de16897a91
* CVE-2024-45777 - Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=b970a5ed967816bbca8225994cd0ee2557bad515
* CVE-2024-45778_CVE-2024-45779 - Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=26db6605036bd9e5b16d9068a8cc75be63b8b630
* CVE-2024-45780 - Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=0087bc6902182fe5cedce2d034c75a79cf6dd4f3
* CVE-2024-45781 - Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=c1a291b01f4f1dcd6a22b61f1c81a45a966d16ba
* CVE-2024-45782_CVE-2024-56737 - Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=417547c10410b714e43f08f74137c24015f8f4c3
* CVE-2024-45783 - Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=f7c070a2e28dfab7137db0739fb8db1dc02d8898

Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>