vgabios-isavga.bin file is incorrectly named

Description:

QEMU fails to initialize when using the isa-vga device:

$ qemu-system-i386 -device isa-vga
Could not open option rom 'vgabios.bin': No such file or directory

This is because vgabios-isavga.bin output file should actually be named vgabios.bin. This is an edge case in the QEMU Makefile; see: https://github.com/qemu/qemu/blob/7425b6277f12e82952cede1f531bfc689bf77fb1/roms/Makefile#L83

I believe the fix should just be a matter of changing https://gitlab.archlinux.org/archlinux/packaging/packages/seabios/-/blob/ebfc652940cf52f4c6b212e8e6b8da1671d8df54/PKGBUILD#L104:

-    [config.vga-isavga]="vgabios.bin vgabios-isavga.bin out/vgabios.bin"
+    [config.vga-isavga]="vgabios.bin vgabios.bin out/vgabios.bin"

Testing this with ln -sf /usr/share/qemu/vgabios-isavga.bin /usr/share/qemu/vgabios.bin shows that QEMU is able to successfully boot with the correct filename.

Additional info:

• package version(s): 1.16.3-1
• config and/or log files: N/A
• link to upstream bug report, if any: N/A

Steps to reproduce:

1. Install the qemu package
2. Run qemu-system-i386 -device isa-vga
3. See that "Could not open option rom 'vgabios.bin': No such file or directory" is printed, and QEMU displays "Guest has not initialized the display (yet)"