build: Cleaned up Android makefiles for legibility.

I triple checked this and verified the build, but would appreciate a
second or third set of eyes to ensure I didn't change anything.

Wanted to make it easier to read the build flags and dependencies.
There are some linker warnings with the latest NDK related to the gnu
stl and thought this might help track it down.
build: Fool-proofed the rsp-hle make file.

Everything is defined exactly once.  Simplifies maintenance, reduces
likelihood of errors.
build: Remove dependency on cpufeatures for most modules.

Only module that currently needs this is gles2n64.
build: Convert tabs to spaces.
build: Removed xperia-touchpad dependency on OpenGL-related libraries.

The leftover OpenGL code was removed way back in November:
5b9eed78c6e200520c726fbd5dd92efb4a87b78a
build: Removed unneeded workaround in core's android makefile.
build: Remove unneeded NO_ASM and ANDROID defines from some modules.
build: Removed linkage to GLESv1 in all modules except SDL.

Removing the linkage from SDL (if it's even possible) will require
careful truncation of the list of compiled source files.

Removing it from the other modules guarantees that they are not making
GLESv1 calls (front-end, gles2n64, gles2rice).
build: Remove GLESv2 linkage from front-end's android makefile.
build: Remove obsolete warning-disabling flags.

These only pertained to GCC 4.4.  The latest NDK toolchain defaults to
GCC 4.6.

Reference:
https://groups.google.com/forum/?fromgroups=#!topic/android-ndk/mrk5dDqWioM
build: Remove other unneeded linkages to standard libraries.

-ldl Dynamic Linker library
    Although the header is included in osal_dynamiclib_unix.c, we are
    apparently not using any of its features in our build.

-llog Android Logging library
    Not needed by audio-sdl or rsp-hle.

-lz ZLib Compression library
    Not needed by png because png is static. Rather, the clients of png
    must link to ZLib (gles2rice).
build: Whitespace tweak and remove redundant flag.

-O3 already includes -fpredictive-commoning.