rom.sh: Name pico directory serprog_pico

Previously serprog_rp2040, but we now also support
the RP2530 boards.

Therefore, serprog_pico is a nice generic name. The
directory on release archives will now be serprog_pico
instead of serprog_rp2040; it will contain serprog images
for both RP2040 and RP2530 devices.

Signed-off-by: Leah Rowe <leah@libreboot.org>

config/data/pico-serprog/mkhelper.cfg

@@ -6,4 +6,4 @@ sersrc="src/pico-serprog"
 serx="$sersrc/build/pico_serprog.uf2"
 picosdk="src/pico-sdk"
 serdir="$picosdk/src/boards/include/boards"
-premake="mkserprog rp2040"
+premake="mkserprog pico"

include/rom.sh

@@ -11,7 +11,7 @@ mkserprog()
 	basename -as .h "$serdir/"*.h > "$TMPDIR/ser" || $err "!mk $1 $TMPDIR"
 
 	while read -r sertarget; do
-		[ "$1" = "rp2040" ] &&
+		[ "$1" = "pico" ] &&
 		    x_ rm -rf "$sersrc/build" \
 		    && (pt=$(x_ grep "pico_cmake_set" \
 		          "$picosdk/src/boards/include/boards/$sertarget.h" \