ARM: OMAP: AM35xx: remove redunant cpu_is checks for AM3505

There are several checks for AM35x devices done using

      if (cpu_is_omap3517() || cpu_is_omap3505())

However, since the 3505 is just a 3517 without an SGX, the 3505 check
is redundant because cpu_is_omap3517() will always be true whenever
cpu_is_omap3505() is true.  From <plat/cpu.h>:

 #define cpu_is_omap3505() (cpu_is_omap3517() && !omap3_has_sgx())

Therefore, remove the redunant 3505 checks.  This helps move towards
removal of SoC detection that depends on specific IP detection.

Acked-by: Vaibhav Hiremath <hvaibhav@ti.com>
Tested-by: Vaibhav Hiremath <hvaibhav@ti.com>
Tested-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>