memory: omap-gpmc: Fix a couple off by ones

These comparisons should be >= instead of > to prevent reading one
element beyond the end of the gpmc_cs[] array.

Fixes: cdd6928c ("ARM: OMAP2+: Add device-tree support for NOR flash")
Fixes: f37e4580 ("ARM: OMAP2: Dynamic allocator for GPMC memory space")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Link: https://lore.kernel.org/r/20200825104707.GB278587@mwanda


Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>