dt-bindings: riscv: fix single letter canonical order

I used the wikipedia table for ordering extensions when updating the
pattern here in commit 299824e6 ("dt-bindings: riscv: add new
riscv,isa strings for emulators").

Unfortunately that table did not match canonical order, as defined by
the RISC-V ISA Manual, which defines extension ordering in (what is
currently) Table 41, "Standard ISA extension names". Fix things up by
re-sorting v (vector) and adding p (packed-simd) & j (dynamic
languages). The e (reduced integer) and g (general) extensions are still
intentionally left out.

Link: https://github.com/riscv/riscv-isa-manual/releases/tag/riscv-unpriv-pdf-from-asciidoc-15112022 # Chapter 29.5
Fixes: 299824e6

 ("dt-bindings: riscv: add new riscv,isa strings for emulators")
Acked-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221205174459.60195-3-conor@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>