gpio: thunderx: Don't directly include asm-generic/msi.h

On architectures that require it, asm-generic/msi.h is already
dragged in by the higher level include files, and is commonly
refered to as 'asm/msi.h'.

It is also architecture specific, and breaks compilation in
a pretty bad way now that linux/gpio/driver.h includes asm/msi.h
(which drags a conflicting but nonetheless correct version
of msi_alloc_info_t on x86).

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220711154252.4b88a601@canb.auug.org.au
Link: https://lore.kernel.org/r/20220711081257.132901-1-maz@kernel.org
Fixes: 91a29af4 ("gpio: Remove dynamic allocation from populate_parent_alloc_arg()")
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Linus Walleij <linus.walleij@linaro.org>